Archive for the ‘climate change – global warming’ Category

Extreme climate threats mean that a new classification is needed

October 30, 2017

New climate risk classification created to account for potential ‘existential’ threats https://www.eurekalert.org/pub_releases/2017-09/uoc–ncr091417.php Researchers identify a one-in-20 chance of temperature increase causing catastrophic damage or worse by 2050

UNIVERSITY OF CALIFORNIA – SAN DIEGO A new study evaluating models of future climate scenarios has led to the creation of the new risk categories “catastrophic” and “unknown” to characterize the range of threats posed by rapid global warming. Researchers propose that unknown risks imply existential threats to the survival of humanity.

These categories describe two low-probability but statistically significant scenarios that could play out by century’s end, in a new study by Veerabhadran Ramanathan, a distinguished professor of climate and atmospheric sciences at Scripps Institution of Oceanography at the University of California San Diego, and his former Scripps graduate student Yangyang Xu, now an assistant professor at Texas A&M University.

The risk assessment stems from the objective stated in the 2015 Paris Agreement regarding climate change that society keep average global temperatures “well below” a 2°C (3.6°F) increase from what they were before the Industrial Revolution.

Even if that objective is met, a global temperature increase of 1.5°C (2.7°F) is still categorized as “dangerous,” meaning it could create substantial damage to human and natural systems. A temperature increase greater than 3°C (5.4°F) could lead to what the researchers term “catastrophic” effects, and an increase greater than 5°C (9°F) could lead to “unknown” consequences which they describe as beyond catastrophic including potentially existential threats. The specter of existential threats is raised to reflect the grave risks to human health and species extinction from warming beyond 5° C, which has not been experienced for at least the past 20 million years.

The scientists term warming probability of five percent or less as a “low-probability high-impact” scenario and assess such scenarios in the analysis “Well Below 2°C: Mitigation strategies for avoiding dangerous to catastrophic climate changes,” which will appear in the journal Proceedings of the National Academy of Sciences on Sept. 14.

Ramanathan and Xu also describe three strategies for preventing the gravest threats from taking place.

“When we say five percent-probability high-impact event, people may dismiss it as small but it is equivalent to a one-in-20 chance the plane you are about to board will crash,” said Ramanathan. “We would never get on that plane with a one-in-20 chance of it coming down but we are willing to send our children and grandchildren on that plane.”

The researchers defined the risk categories based on guidelines established by the Intergovernmental Panel on Climate Change (IPCC) and previous independent studies. “Dangerous” global warming includes consequences such as increased risk of extreme weather and climate events ranging from more intense heat waves, hurricanes, and floods, to prolonged droughts. Planetary warming between 3°C and 5°C could trigger what scientists term “tipping points” such as the collapse of the West Antarctic Ice Sheet and subsequent global sea-level rise, and the dieback of the Amazon rainforest. In human systems, catastrophic climate change is marked by deadly heat waves becoming commonplace, exposing over 7 billion people to heat related mortalities and famine becoming widespread. Furthermore, the changes will be too rapid for most to adapt to, particularly the less affluent, said Ramanathan.

Risk assessments of global temperature rise greater than 5°C have not been undertaken by the IPCC. Ramanathan and Xu named this category “unknown??” with the question marks acknowledging the “subjective nature of our deduction.” The existential threats could include species extinctions and major threats to human water and food supplies in addition to the health risks posed by exposing over 7 billion people worldwide to deadly heat.

With these scenarios in mind, the researchers identified what measures can be taken to slow the rate of global warming to avoid the worst consequences, particularly the low-probability high-impact events. Aggressive measures to curtail the use of fossil fuels and emissions of so-called short-lived climate pollutants such as soot, methane and HFCs would need to be accompanied by active efforts to extract CO2 from the air and sequester it before it can be emitted. It would take all three efforts to meet the Paris Agreement goal to which countries agreed at a landmark United Nations climate conference in Nov 2015.

Xu and Ramanathan point out that the goal is attainable. Global CO2 emissions had grown at a rate of 2.9 percent per year between 2000 and 2011, but had slowed to a near-zero growth rate by 2015. They credited drops in CO2 emissions from the United States and China as the primary drivers of the trend. Increases in production of renewable energy, especially wind and solar power, have also bent the curve of emissions trends downward. Other studies have estimated that there was by 2015 enough renewable energy capacity to meet nearly 24 percent of global electricity demand.

Short-lived climate pollutants are so called because even though they warm the planet more efficiently than carbon dioxide, they only remain in the atmosphere for a period of weeks to roughly a decade whereas carbon dioxide molecules remain in the atmosphere for a century or more. The authors also note that most of the technologies needed to drastically curb emissions of short-lived climate pollutants already exist and are in use in much of the developed world. They range from cleaner diesel engines to methane-capture infrastructure.

“While these are encouraging signs, aggressive policies will still be required to achieve carbon neutrality and climate stability,” the authors wrote.

The release of the study coincides with the start of Climate Week NYC in New York, a summit of business and government leaders to highlight global climate action. Ramanathan and colleagues will deliver a complementary report detailing the “three-lever” mitigation strategy of emissions control and carbon sequestration on Sept. 18 at the United Nations. That report was produced by the Committee to Prevent Extreme Climate Change, chaired by Ramanathan, Nobel Prize winner Mario Molina of UC San Diego, and Durwood Zaelke, who leads an advocacy organization, the Institute for Governance and Sustainable Development, with 30 experts from around the world including China and India.

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Satellites reveal sea level rise

October 30, 2017

Global fingerprints of sea-level rise revealed by satellites, http://www.nature.com/news/global-fingerprints-of-sea-level-rise-revealed-by-satellites-1.22588

Geological processes send more meltwater from glaciers and ice sheets to Earth’s mid-latitudes. Rachael Lallensack, As an ice sheet melts, it leaves a unique signature behind. Complex geological processes distribute the meltwater in a distinct pattern, or ‘fingerprint’, that causes seas to rise unevenly around the world. Now, for the first time, researchers have observed what these sea-level fingerprints look like on a global scale.

“No one has put it together for a complete global picture like this before,” says James Davis, a geophysicist at Columbia University in Palisades, New York. The work was published in Geophysical Research Letters on 9 September1.

The concept of sea-level fingerprints has been been factored into models used to predict sea-level rise for several years, says lead researcher Isabella Velicogna, a geophysicist at the University of California, Irvine. And researchers have used tide gauges for just as long to observe the fingerprints in coastal regions. But the global view provided by the latest study adds confidence to projections of future sea-level rise.

As an ice sheet melts, it leaves a unique signature behind. Complex geological processes distribute the meltwater in a distinct pattern, or ‘fingerprint’, that causes seas to rise unevenly around the world. Now, for the first time, researchers have observed what these sea-level fingerprints look like on a global scale.

“No one has put it together for a complete global picture like this before,” says James Davis, a geophysicist at Columbia University in Palisades, New York. The work was published in Geophysical Research Letters on 9 September1.

The concept of sea-level fingerprints has been been factored into models used to predict sea-level rise for several years, says lead researcher Isabella Velicogna, a geophysicist at the University of California, Irvine. And researchers have used tide gauges for just as long to observe the fingerprints in coastal regions. But the global view provided by the latest study adds confidence to projections of future sea-level rise.

Velicogna and co-author Chia-Wei Hsu, also at the University of California, Irvine, used gravity data from NASA’s two Gravity Recovery and Climate Experiment (GRACE) satellites, which measure changes in mass on Earth’s surface. The scientists looked at satellite data from April 2002 to October 2014, and matched it with measurements from pressure stations on the ocean floor. These instruments measure the total mass above them.

Velicogna says that the findings should be used to create a roadmap for better placement of ocean-bottom pressure stations, which in turn can be used to improve calculations of sea-level fingerprints in the future.

“We know sea-level change throughout the world won’t be uniform, and it’s useful for people to know how those changes might show up,” says Mark Tamisiea, a geophysicist at the University of Texas at Austin.

Role of climate change in Hurricanes Irma and Harvey

October 30, 2017

Irma and Harvey should kill any doubt that climate change is real, We can’t afford to keep pretending. September 7 As we begin to clean up from Hurricane Harvey, the wettest hurricane on record, dumping up to 50 inches of rain on Houston in three days, and await landfall of Irma, the most powerful hurricane on record in the open Atlantic Ocean, people are asking: What is the role of human-induced climate change in these events, and how else have our own actions increased our risks?

Fundamental physical principles and observed weather trends mean we already know some of the answers — and we have for a long time.

Hurricanes get their energy from warm ocean waters, and the oceans are warming because of the human-caused buildup of heat-trapping gases in the atmosphere, primarily from the burning of coal, oil and gas. The strongest hurricanes have gotten stronger because of global warming. Over the past two years, we have witnessed the most intense hurricanes on record for the globe, both hemispheres, the Pacific and now, with Irma, the Atlantic.

We also know that warmer air holds more moisture, and the amount of water vapor in the atmosphere has increased because of human-induced global warming. We’ve measured this increase, and it has been unequivocally attributed to human-caused warming. That extra moisture causes heavier rainfall, which has also been observed and attributed to our influence on climate. We know that rainfall rates in hurricanes are expected to increase in a warmer world, and now we’re living that reality.

And global warming also means higher sea levels, both because ocean water expands as it warms and because ice in the mountains and at the poles melts and makes its way into oceans. Sea level rise is accelerating, and storm surge from hurricanes rides on top of higher seas to infiltrate further into our coastal cities.

Heavier rain and higher sea levels can combine to compound flooding in major hurricanes, as the deluges cause flooding that must drain to the sea but can’t do so as quickly because of storm surges. Sadly, we saw this effect in play in the catastrophic flooding from Harvey.

We don’t have all of the answers yet. There are scientific linkages we’re still trying to work out. Harvey, like Hurricane Irene before it in 2011, resulted in record flooding, because of a combination of factors. Very warm ocean temperatures meant more moisture in the atmosphere to produce heavy rainfall, yes. But both storms were also very slow-moving, nearly stationary at times, which means that rain fell over the same areas for an extended period.

Cutting-edge climate science suggests that such stalled weather patterns could result from a slowed jet stream, itself a consequence — through principles of atmospheric science — of the accelerated warming of the Arctic. This is a reminder of how climate changes in far-off regions such as the North Pole can have very real effects on extreme weather faced here in the Lower 48.

These linkages are preliminary, and scientists are still actively studying them. But they are a reminder that surprises may be in store — and not welcome ones — when it comes to the unfolding effects of climate change.

Which leads us, inevitably, to a discussion of policy — and, indeed, politics. Previous administrations focused on adapting to climate change, with an eye to what the planet would look like in the future. But events such as Harvey, and probably Irma, show that we have not even adapted to our current climate (which has already changed because of our influence).

The effects of climate change are no longer subtle. We are seeing them play out before us here and now. And they will only worsen if we fail to act.

The Trump administration, however, seems determined to lead us backward. In recent months, we have witnessed a dismantling of the policies put in place by the Obama administration to (a) incentivize the necessary move from climate-change-producing fossil fuels toward clean energy, (b) increase resilience to climate change effects through sensible regulations on coastal development, and (c) continue to fund basic climate research that can inform our assessments of risk and adaptive strategies. Ironically, just 10 days before Harvey struck, President Trump rescinded flood protection standards put in place by the Obama administration that would take sea level rise and other climate change effects into account in coastal development plans.

And as Trump kills policies that would reduce the risks of climate disasters, our nation continues to support policies that actually increase our risks. For example, without the taxpayer-subsidized National Flood Insurance Program, banks would be less likely to provide mortgages for rebuilding houses in locations that have been flooded before, sometimes repeatedly. And the flood insurance program is itself underwater:  badly in debt and set to expire at the end of this month unless Congress finds a way to keep it afloat, just as billions of dollars in claims from Harvey come pouring in.

Harvey and Irma are sad reminders that policy matters. At a time when damage from climate change is escalating, we need sensible policy in Washington to protect the citizens of this country, both by reducing future climate change and preparing for its consequences. We should demand better of our leaders.

Climate change: its effects on the world’s most important food crops

October 30, 2017

Climate Change Already Impacting Wheat, Rice, Corn, Soybean Yields Worldwide,  https://www.forbes.com/sites/jeffmcmahon/2017/09/01/climate-change-already-impacting-wheat-rice-corn-soybean-yields-worldwide/#6a3501b3777b  ,  

Increased temperatures from climate change will reduce yields of the four crops humans depend on most—wheat, rice, corn and soybeans—and the losses have already begun, according to a new meta-study by an international team of researchers.

Humans depend for two thirds of their calories on these four staple crops, but yields of wheat are expected to decrease by 6%, rice by 3.2%, maize by 7.4%, and soybean by 3.1%.

“By combining four different methods, our comprehensive assessment of the impacts of increasing temperatures on major global crops shows substantial risks for agricultural production, already stagnating in some parts of the world,” the scientists say in the study, which appears in the latest issue of the Proceedings of the National Academy of Sciences.

“Yield increase has slowed down or even stagnated during the last years in some parts of the world, and further increases in temperature will continue to suppress yields, despite farmers’ adaptation efforts.” The study, led by Chuang Zhao of Peking University, cites three other studies documenting declines in crop yields in Europe, Africa, India, China, Central and South America and other regions.

The study of studies was conducted by scientists in China, Germany, Belgium, Italy, France, Spain, The Philippines, and the United States, including the University of Florida, Stanford University, the University of Chicago, and Columbia University in New York. They hoped to settle a question that seemed to have produced conflicting results in the many studies they reviewed: what are the effects on crop yields of temperature increases from anthropogenic climate change?

 The study rebuts an argument made by those who argue against mitigating climate change because they say higher CO2 concentrations will increase crop yields. That argument, the scientists say, fails to account for higher temperatures:

“While elevated atmospheric CO2 concentration can stimulate growth when nutrients are not limited, it will also increase canopy temperature from more closed stomata,” the scientists say. The stomata are the pores plants use to exchange gases and moisture with the atmosphere. When plants close stomata because of higher temperatures they may conserve water but lose the ability to absorb CO2.

Higher temperatures can also increase atmospheric absorption of water in the plants and in the soil, provoke heat waves and stimulate pests and weeds.

The study anticipates that crop yields will improve in some areas because higher temperatures will lengthen the growing season, but it finds net losses worldwide.

The scientists acknowledge uncertainty about the interactions between temperature, rainfall and increased CO2 concentrations in different regions. They note that different crops respond differently in different regions and under different conditions, so they call for increased local analysis and local strategies:

“Differences in temperature responses of crops around the world suggest that some mitigation could be possible to substantially affect the magnitude (or even direction) of climate change impacts on agriculture. These impacts will also vary substantially for crops and regions, and may interact with changes in precipitation and atmospheric CO2, so a reinvigoration of national research and extension programs is urgently needed to offset future impacts of climate change, including temperature increase on agriculture by using crop- and region-specific adaptation strategies.”

By Jeff McMahon, based in Chicago. Follow Jeff McMahon on FacebookGoogle PlusTwitter, or email him here.

Climate change and infectious diseases

October 30, 2017

the pathogen with the highest sensitivity to climate factors was Vibrio cholera, the microbe that causes the serious, and often deadly, diarrheal disease, cholera. Cholera had nine climate drivers, indicating high volatility in the face of climate change.

These Infections Are Likely to Get Worse as the Climate Changes, Invisiverse, BY CYNTHIA WALLENTINE, 08/23/2017

When the climate changes, so do all the things that rely on the climate, including people, plants, and pathogens. A European study recently took a broad look at what kind of microorganisms are most likely to be affected as climate change heats, cools, dries, and wets the world around us.

In a study published in the journal Scientific Reports, a research team from the University of Liverpool performed a broad assessment of how factors of climate change impact pathogens that make humans and animals sick. By understanding which microorganisms are more sensitive to environmental change, we have a better idea of how infection rates might change as the environment grows progressively less stable.

What Are Climate Drivers?

In the study, the authors note there is evidence that climate shifts are already causing changes in the incidence of disease — allowing some to appear at higher or lower altitudes and latitudes. The authors note modeling is frequently used to predict which pathogens could advance, but this study uses climate variables, along with data on selected pathogens, to get an idea of which pathogens we should worry about the most.

Climate variables that affect these pathogens are an important part of this study. The research team refers to these variables as “climate drivers” that include:

Primary drivers: Extreme weather events, climate change, climate oscillations, moisture, rainfall, temperature, and wind fluctuations.

Secondary drivers: Altitude, salinity, particulate matter, and vegetation.

The team chose to analyze 101 pathogens considered “high impact” to humans and animals in Europe and categorized them by how sensitive they are to these factors. These pathogens included bacteria, fungi, helminths, protozoa, and viruses. Overall, there are 157 pathogens categorized because some pathogens are affected by both primary and secondary variables.

Which Pathogens Are Set to Be Destabilized by Climate Change?

Humans, animals, plants, and microorganisms rely on climate variables that are always in some local flux. When climate drivers swing far enough beyond the expected spectrum, larger change is bound to happen.

When comparing pathogens to climate drivers, the study team found that 99, or 63% of the pathogens were likely to respond to at least one climate driver. Fifty-eight, or 37%, of the pathogens, like HIV, did not show sensitivity to climate variables. That narrows the field of pathogens likely to go askew because of environmental change.

More than 90% of that initial group of 99 pathogens were sensitive to between one and five climate drivers. Other statistical findings on the numbers of pathogens likely to be affected by climate change include:

  • 81 of 99 pathogens were affected by primary climate drivers
  • 56 of the 99 pathogens also had secondary climate drivers
  • 18 of the 99 agents had sensitivity to secondary, but not primary climate drivers

Overall, pathogens were found to be most sensitive to climate drivers (primary and secondary) that include rainfall, temperature, moisture, and particulate matter.

  • The pathogen with the highest sensitivity to climate factors was Vibrio cholera, the microbe that causes the serious, and often deadly, diarrheal disease, cholera. Cholera had nine climate drivers, indicating high volatility in the face of climate change.
  • First runner up was the helminth, a parasite known as the “liver fluke” found throughout the world where sheep and cattle are present. A “helminth,” is the term for any parasitic nematode, worm, or fluke.
  • Next up is anthrax, Bacillus anthracis, a naturally occurring bacteria that can prove fatal depending on infection type, and available treatment.
  • Rounding out the top four is Borrelia burgdorferi, the tick-borne bacteria that causes Lyme disease. (We’re already seeing increased incidence of Lyme-bearing ticks in the Northeast US.)

……. https://www.invisiverse.com/news/deadlier-when-hot-these-infections-are-likely-get-worse-as-climate-changes-0179252/

Most Americans believe that human-caused climate change is real

July 24, 2017

New Survey Shows Majority Of Americans Believe Climate Change Is Real And Caused By Human Activity  https://www.desmogblog.com/2017/07/06/new-survey-shows-majority-americans-believe-climate-change-real-and-caused-human-activity?utm_source=dsb%20newsletter  By Farron Cousins • Thursday, July 6, 2017 The current leadership in the United States — the U.S. House of Representatives, the Senate, and the White House — have a hostile relationship with climate change science. Not only has current President Donald Trump suggested that the entire concept is a hoax perpetrated by the Chinese, but the Legislative Branch of government is populated with a majority of representatives who do not accept the scientific consensus regarding climate change. Not only are these views dangerous for the future of the planet, but a new poll shows that these views are entirely out of sync with a majority of the U.S. population.

According to a new report by the Yale Program on Climate Change Communication, a majority of people in the United States believe that climate change is real and that it is mostly the result of human activities. The survey shows that 58% of the public now accepts that climate change is mostly caused by human activity, which is the highest level ever recorded of public acceptance of the human role in climate change since Yale began conducting these studies in 2008.

Here are a few key findings from the new report:

Over half of Americans (58%) understand that global warming is mostly human caused, the highest level since our surveys began in November 2008. By contrast, three in ten (30%) say it is due mostly to natural changes in the environment – the lowest level recorded since 2008.

Only about one in eight Americans (13%) understand that nearly all climate scientists (more than 90%) are convinced that human-caused global warming is happening.

Over half of Americans (57%) say they are at least “somewhat worried” about global warming. About one in six (17%) are “very worried” about it.

About one in three Americans (35%) think people in the U.S. are being harmed by global warming “right now.”

By a large margin, Americans say that schools should teach children about the causes, consequences, and potential solutions to global warming (78% agree vs. 21% who disagree).

One particularly intriguing finding from the Yale report is that the majority believe that the threats of climate change are things that will either happen in the distant future, or that they will not happen to the individuals polled or their families:

Most Americans think global warming is a relatively distant threat – they are most likely to think that it will harm future generations of people (71%), plant and animal species (71%), the Earth (70%), people in developing countries (62%), or the world’s poor (62%). They are less likely to think it will harm people in the U.S. (58%), their own grandchildren (56%) or children (50%), people in their community (48%), their family (47%), themselves (43%), or members of their extended family living outside the U.S. (41%).

The fact that most Americans either believe the threat is something that will happen in the distant future or that it won’t happen to them is one possible reason so many people are willing to vote for politicians who either outright deny the existence of climate change or who refuse to act on the issue. Currently, a majority of members of both the U.S. House and the U.S. Senate fall into one of those categories, with 53 out of 100 U.S. Senators counted as climate change deniers and 232 out of 435 House members listed as deniers.

But the truth is that climate change is not a far-off threat for Americans. Rising sea levels are already threatening drinking water in South Florida, as salt water is seeping into aquifers. Elsewhere, rising temperatures, rising sea levels, changes in precipitation patterns, and extreme weather events that have been linked to climate change are wreaking havoc. So one of the main focuses of climate science advocates needs to be educating people about the timeline so they stop viewing climate change as a problem that can be put on the back burner. It is happening right now.

Nevertheless, the fact that a majority of U.S. citizens understand the realities of climate change while our elected leaders refuse to accept the science indicates that they have become too far removed from the values, desires, and concerns of their constituents. That’s likely due in part to the massive amounts of money that fossil fuel companies spend on lobbying and direct campaign contributions which totaled $120+ million and $103 million in 2016, respectively.

 

The world will continue to have deadly heatwaves – and rising

July 24, 2017

Deadly heatwaves expected to continue to rise https://www.sciencedaily.com/releases/2017/06/170619120507.htm

Date:
June 19, 2017
Source:
University of Hawaii at Manoa
Summary:
Seventy-four percent of the world’s population will be exposed to deadly heatwaves by 2100 if carbon gas emissions continue to rise at current rates, according to a new study. Even if emissions are aggressively reduced, the percent of the world’s human population affected is expected to reach 48 percent.

Seventy-four percent of the world’s population will be exposed to deadly heatwaves by 2100 if carbon gas emissions continue to rise at current rates, according to a study published in Nature Climate Change. Even if emissions are aggressively reduced, the percent of the world’s human population affected is expected to reach 48 percent.

“We are running out of choices for the future,” said Camilo Mora, associate professor of Geography in the College of Social Sciences at the University of Hawaii at Manoa and lead author of the study. “For heatwaves, our options are now between bad or terrible. Many people around the world are already paying the ultimate price of heatwaves, and while models suggest that this is likely to continue, it could be much worse if emissions are not considerably reduced. The human body can only function within a narrow range of core body temperatures around 37oC. Heatwaves pose a considerable risk to human life because hot weather, aggravated with high humidity, can raise body temperature, leading to life threatening conditions.”

A team of researchers lead by Mora conducted an extensive review and found over 1,900 cases of locations worldwide where high ambient temperatures have killed people since 1980. By analyzing the climatic conditions of 783 lethal heat episodes for which dates were obtained, researchers identified a threshold beyond which temperatures and humidities become deadly. The area of the planet where such a threshold is crossed for 20 or more days per year has been increasing and is projected to grow even with dramatic cuts in greenhouse gas emissions. Currently, about 30% of the world’s human population is exposed to such deadly conditions each year.

Numerous examples, such as the 2003 European heatwave that killed approximately 70,000 people, the 2010 Moscow heatwave that killed 10,000 people and the 1995 Chicago heatwave that killed 700 people are staggering examples of the risk to life posed by heatwaves. But beyond these highly cited examples, little was known about how common such killer heatwaves are.

The international group of researchers and students coordinated by the University of Hawaii at Manoa set out to answer that question. From over 30,000 relevant publications, the researchers identified 911 papers with data on 1,949 case studies of cities or regions, where human deaths were associated with high temperatures. From those cases, dates were obtained for 783 lethal heatwaves in 164 cities across 36 countries, with most cases recorded in developed countries at mid-latitudes. Some of the cities that have experienced lethal heatwaves included New York, Washington, Los Angeles, Chicago, Toronto, London, Beijing, Tokyo, Sydney and Sao Paulo.

When analyzing the climatic conditions for those cities, the researchers discovered a common threshold beyond which temperatures and humidities became lethal. In agreement with human thermal physiology, the threshold was such that as relative humidity increases, lower temperatures become lethal.

“Finding a threshold beyond which climatic conditions turn deadly is scientifically important yet frightening,” said Farrah Powell, a UH Manoa graduate student and one of the co-authors in the study. “This threshold now allows us to identify conditions that are harmful to people. And because it is based on documented cases of real people across the globe, it makes it that more credible and relevant. The scary thing is how common those deadly conditions are already.”

A web-application accompanying the paper allows counting, for any place on Earth, the number of days in a year when temperature and humidity exceed such a deadly threshold. For example, by 2100 New York is projected to have around 50 days with temperatures and humidities exceeding the threshold in which people have previously died. That same year, the number of deadly days for Sydney will be 20, 30 for Los Angeles, and the entire summer for Orlando and Houston.

The study also found that the greatest risk to human life from deadly heat was projected for tropical areas. This is because the tropics are hot and humid year round, whereas for higher latitudes the risk of deadly heat is restricted to summer.

“Warming at the poles has been one of the iconic climatic changes associated with the ongoing emissions of greenhouse gases,” said co-author Iain Caldwell, a UH Manoa post-doctoral researcher. “Our study shows, however, that it is warming in the tropics that will pose the greatest risk to people from deadly heat events. With high temperatures and humidities, it takes very little warming for conditions to turn deadly in the tropics.”

“Climate change has put humanity on a path that will become increasingly dangerous and difficult to reverse if greenhouse gas emissions are not taken much more seriously,” says Mora. “Actions like the withdrawal from the Paris agreement is a step in the wrong direction that will inevitably delay fixing a problem for which there is simply no time to waste.”

Climate deniers in action

July 24, 2017

How To Dismantle A Nuclear Weapon, Gizmodo, Terrell Jermaine Starr and Jalopnik, May 24, 2017  “…..Getting Rid Of Plutonium Is Harder

For one, there is no civilian use for plutonium in the United States because you can’t break it down or blend it. In other words, it is always ready to be used for weapons. In fact, according to Live Science, of its five common isotopes, only plutonium-238 and plutonium-239 are used for anything.

Pu-238 is used for powering space probes and Pu-239, the isotope we’re talking about, goes through a fission chain reaction when concentrated enough. And when that process takes place, it is nuke-ready.

By the way, Plutonium is pretty damn radioactive and contains the “worst kind of fission byproducts that could enter the environment as a result of the Fukushima nuclear disaster,” as Live Science notes (emphasis ours):

According to the Environmental Protection Agency, plutonium enters the bloodstream via the lungs, then moves throughout the body and into the bones, liver, and other organs. It generally stays in those places for decades, subjecting surrounding organs and tissues to a continual bombardment of alpha radiation and greatly increasing the risk of cancer, especially lung cancer, liver cancer and bone sarcoma.

There are documented cases of workers at nuclear weapons facilities dying within days of experiencing brief accidental exposure to plutonium, according to the Hazardous Substances Data Bank.

Furthermore, among all the bad things coming out of Fukushima, plutonium will stay in the environment the longest. One isotope of plutonium, Pu-239, has a half-life of 24,100 years; that’s the time it will take for half of the stuff to radioactively decay. Radioactive contaminants are dangerous for 10 to 20 times the length of their half-lives, meaning that dangerous plutonium released to the environment today will stick around for the next half a million years.

That is why Japan’s reported goal to use plutonium for civilian reactors have the U.S. and China worried. At one point, Japan had around 10 tons of unseparated plutonium in-country; 37.1 tons are in France and the United Kingdom. China fears Toyko could possibly use the plutonium to develop nuclear weapons, although the Japanese did give up 331kg of it in 2016.

Collina said it’s a good thing the U.S. has no plans to use plutonium for civilian purposes.

“You can’t blend down plutonium,” he says. “It’s always weapons-usable. So if you use this stuff at nuclear power plants, you’re basically spreading weapons-usable nuclear material all around. It’s a proliferation problem because we don’t want to set the example for other nations to say, ‘I’m going to use plutonium in my civilian power program’ and therefore create a cover for a secret weapons program. We want to have a pretty clear line that says, ‘Plutonium is only used for weapons and you should not use plutonium if you’re not using it for weapons.'”

As for actually getting rid of plutonium, the process is not environmentally friendly and it never will be. Most of the plutonium that is separated from nukes is stored at the Savannah River Site (SRS), near the Georgia border. Plutonium is also stored at the Pantex Plant. It’s authorised to store 20,000 plutonium pits; current estimates find that 14,000 are stored in the facility.

But here’s the catch: you can never make it truly safe, and no one wants it near them. For example, the Department of Energy, through the Nuclear Regulatory Commission, is currently overseeing construction of a facility at SRS to make MOX fuel from weapons-ready plutonium. It would then be used for commercial use.

The problem is that no one wants plutonium storage facilities in their backyards. The American ambassador to the United Nations, Nikki Haley, expressed concerns over the MOX fuel initiative when she was governor of South Carolina. Her issue was that the feds were supposed to remove a ton of plutonium from the state by January 2016 and ship it to another facility in New Mexico or process it for commercial use through the facility; neither happened, so she sued the Department of Energy. A federal circuit court dismissed the case.

Officially, MOX fuel is not being used in the United States, according to the Nuclear Regulatory Commission. Europe uses MOX fuel, but its plutonium is from spent nuclear fuel rather than nuclear weapons.

Former Nevada Senator Harry Reid resisted the Yucca Mountain Nuclear Waste Repository project, which was supposed to be a deep geological repository storage facility for spent nuclear fuel and radioactive waste like Pu-239. Under the Nuclear Waste Policy Act amendments of 1987, the Yucca Mountains were supposed to be the key destination for storing this waste, but Reid worked with Obama to end funding for the project.

Where To Send It?

So, if no one wants plutonium in their backyard here on planet earth, where can it be disposed? Well, there have been a bunch of wild ideas, like blasting it into the sun. Which, as the video below explains, is a pretty bad idea.

Hitting the Sun is HARD

You also have to factor in the possibility the space ship won’t make it to orbit. “Space shuttles crash,” Collina said. “So if you had just one crash with a space shuttle full of plutonium, that would ruin your whole day.”

The best plan of action the feds have to deal with weapons-ready plutonium is to simply store it someplace — a place where folks won’t complain to much about it. Good luck finding such a place.https://www.gizmodo.com.au/2017/05/how-to-dismantle-a-nuclear-weapon/

Global warming is affecting the world’s lakes

May 18, 2017

Lakes worldwide feel the heat from climate change, Warming waters are disrupting freshwater fishing and recreation, Science News ,BY ALEXANDRA WITZE  MAY 1, 2017 “……..When most people think of the physical effects of climate change, they picture melting glaciers, shrinking sea ice or flooded coastal towns (SN: 4/16/16, p. 22). But observations like those at Stannard Rock are vaulting lakes into the vanguard of climate science. Year after year, lakes reflect the long-term changes of their environment in their physics, chemistry and biology. “They’re sentinels,” says John Lenters, a limnologist at the University of Wisconsin–Madison.

Globally, observations show that many lakes are heating up — but not all in the same way or with the same ecological consequences. In eastern Africa, Lake Tanganyika is warming relatively slowly, but its fish populations are plummeting, leaving people with less to eat. In the U.S. Upper Midwest, quicker-warming lakes are experiencing shifts in the relative abundance of fish species that support a billion-dollar-plus recreational industry. And at high global latitudes, cold lakes normally covered by ice in the winter are seeing less ice year after year — a change that could affect all parts of the food web, from algae to freshwater seals.

Understanding such changes is crucial for humans to adapt to the changes that are likely to come, limnologists say. Indeed, some northern lakes will probably release more methane into the air as temperatures rise — exacerbating the climate shift that is already under way.

Lake layers

Lakes and ponds cover about 4 percent of the land surface not already covered by glaciers. That may sound like a small fraction, but lakes play a key role in several planetary processes. Lakes cycle carbon between the water’s surface and the atmosphere. They give off heat-trapping gases such as
carbon dioxide and methane, while simultaneously tucking away carbon in decaying layers of organic muck at lake bottoms. They bury nearly half as much carbon as the oceans do.

Yet the world’s more than 100 million lakes are often overlooked in climate simulations. That’s surprising, because lakes are far easier to measure than oceans. Because lakes are relatively small, scientists can go out in boats or set out buoys to survey temperature, salinity and other factors at different depths and in different seasons.

A landmark study published in 2015 aimed to synthesize these in-water measurements with satellite observations for 235 lakes worldwide. In theory, lake warming is a simple process: The hotter the air above a lake, the hotter the waters get. But the picture is far more complicated than that, the international team of researchers found.

Globally, observations show that many lakes are heating up — but not all in the same way or with the same ecological consequences. In eastern Africa, Lake Tanganyika is warming relatively slowly, but its fish populations are plummeting, leaving people with less to eat. In the U.S. Upper Midwest, quicker-warming lakes are experiencing shifts in the relative abundance of fish species that support a billion-dollar-plus recreational industry. And at high global latitudes, cold lakes normally covered by ice in the winter are seeing less ice year after year — a change that could affect all parts of the food web, from algae to freshwater seals.

Understanding such changes is crucial for humans to adapt to the changes that are likely to come, limnologists say. Indeed, some northern lakes will probably release more methane into the air as temperatures rise — exacerbating the climate shift that is already under way.

Lake layers

Lakes and ponds cover about 4 percent of the land surface not already covered by glaciers. That may sound like a small fraction, but lakes play a key role in several planetary processes. Lakes cycle carbon between the water’s surface and the atmosphere. They give off heat-trapping gases such as
carbon dioxide and methane, while simultaneously tucking away carbon in decaying layers of organic muck at lake bottoms. They bury nearly half as much carbon as the oceans do.

Yet the world’s more than 100 million lakes are often overlooked in climate simulations. That’s surprising, because lakes are far easier to measure than oceans. Because lakes are relatively small, scientists can go out in boats or set out buoys to survey temperature, salinity and other factors at different depths and in different seasons.

A landmark study published in 2015 aimed to synthesize these in-water measurements with satellite observations for 235 lakes worldwide. In theory, lake warming is a simple process: The hotter the air above a lake, the hotter the waters get. But the picture is far more complicated than that, the international team of researchers found.

On average, the 235 lakes in the study warmed at a rate of 0.34 degrees Celsius per decade between 1985 and 2009. Some warmed much faster, like Finland’s Lake Lappajärvi, which soared nearly 0.9 degrees each decade. A few even cooled, such as Blue Cypress Lake in Florida. Puzzlingly, there was no clear trend in which lakes warmed and which cooled. The most rapidly warming lakes were scattered across different latitudes and elevations.

Even some that were nearly side by side warmed at different rates from one another — Lake Superior, by far the largest of the Great Lakes, is warming much more rapidly, at a full degree per decade, than others in the chain, although Huron and Michigan are also warming fast.

“Even though lakes are experiencing the same weather, they are responding in different ways,” says Stephanie Hampton, an aquatic biologist at Washington State University in Pullman.

Such variability makes it hard to pin down what to expect in the future. But researchers are starting to explore factors such as lake depth and lake size (intuitively, it’s less teeth-chattering to swim in a small pond in early summer than a big lake).

Depth and size play into stratification, the process through which some lakes separate into layers of different temperatures. …….https://www.sciencenews.org/article/lakes-worldwide-feel-heat-climate-change?tgt=nr

The vanishing Arctic ice

May 18, 2017

The hard truth, however, is that the Arctic as it is known today is almost certainly gone. Efforts to mitigate global warming by cutting emissions remain essential. But the state of the Arctic shows that humans cannot simply undo climate change. They will have to adapt to it

The Arctic as it is known today is almost certainly gone On current trends, the Arctic will be ice-free in summer by 2040 http://www.economist.com/news/leaders/21721379-current-trends-arctic-will-be-ice-free-summer-2040-arctic-it-known-today?fsrc=scn/tw/te/bl/ed/climatechangethearcticasitisknowntodayisalmostcertainlygone Apr 29th 2017

THOSE who doubt the power of human beings to change Earth’s climate should look to the Arctic, and shiver. There is no need to pore over records of temperatures and atmospheric carbon-dioxide concentrations. The process is starkly visible in the shrinkage of the ice that covers the Arctic ocean. In the past 30 years, the minimum coverage of summer ice has fallen by half; its volume has fallen by three-quarters. On current trends, the Arctic ocean will be largely ice-free in summer by 2040.

Climate-change sceptics will shrug. Some may even celebrate: an ice-free Arctic ocean promises a shortcut for shipping between the Pacific coast of Asia and the Atlantic coasts of Europe and the Americas, and the possibility of prospecting for perhaps a fifth of the planet’s undiscovered supplies of oil and natural gas. Such reactions are profoundly misguided. Never mind that the low price of oil and gas means searching for them in the Arctic is no longer worthwhile. Or that the much-vaunted sea passages are likely to carry only a trickle of trade. The right response is fear. The Arctic is not merely a bellwether of matters climatic, but an actor in them (see Briefing).

The current period of global warming that Earth is undergoing is caused by certain gases in the atmosphere, notably carbon dioxide. These admit heat, in the form of sunlight, but block its radiation back into space, in the form of longer-wavelength infra-red. That traps heat in the air, the water and the land. More carbon dioxide equals more warming—a simple equation. Except it is not simple. A number of feedback loops complicate matters. Some dampen warming down; some speed it up. Two in the Arctic may speed it up quite a lot.

One is that seawater is much darker than ice. It absorbs heat rather than reflecting it back into space. That melts more ice, which leaves more seawater exposed, which melts more ice. And so on. This helps explain why the Arctic is warming faster than the rest of the planet. The deal on climate change made in Paris in 2015 is meant to stop Earth’s surface temperature rising by more than 2°C above pre-industrial levels. In the unlikely event that it is fully implemented, winter temperatures over the Arctic ocean will still warm by between 5° and 9°C compared with their 1986-2005 average.

The second feedback loop concerns not the water but the land. In the Arctic much of this is permafrost. That frozen soil locks up a lot of organic material. If the permafrost melts its organic contents can escape as a result of fire or decay, in the form of carbon dioxide or methane (which is a more potent greenhouse gas than CO2). This will speed up global warming directly—and the soot from the fires, when it settles on the ice, will darken it and thus speed its melting still more.

Dead habitat walking

 A warming Arctic could have malevolent effects. The world’s winds are driven in large part by the temperature difference between the poles and the tropics. If the Arctic heats faster than the tropics, this difference will decrease and wind speeds will slow—as they have done, in the northern hemisphere, by between 5 and 15% in the past 30 years. Less wind might sound desirable. It is not. One consequence is erratic behaviour of the northern jet stream, a circumpolar current, the oscillations of which sometimes bring cold air south and warm air north. More exaggerated oscillations would spell blizzards and heatwaves in unexpected places at unexpected times.

Ocean currents, too, may slow. The melting of Arctic ice dilutes salt water moving north from the tropics. That makes it less dense, and thus less inclined to sink for the return journey in the ocean depths. This slowing of circulation will tug at currents around the world, with effects on everything from the Indian monsoon to the pattern of El Niño in the Pacific ocean.

The scariest possibility of all is that something happens to the ice cap covering Greenland. This contains about 10% of the world’s fresh water. If bits of it melted, or just broke free to float in the water, sea levels could rise by a lot more than today’s projection of 74cm by the end of the century. At the moment, the risk of this happening is hard to assess because data are difficult to gather. But loss of ice from Greenland is accelerating.

What to do about all this is a different question. Even if the Paris agreement is stuck to scrupulously, the amount of carbon dioxide already in the atmosphere, together with that which will be added, looks bound eventually to make summer Arctic sea ice a thing of the past. Some talk of geoengineering—for example, spraying sulphates into the polar air to reflect sunlight back into space, or using salt to seed the creation of sunlight-blocking clouds. Such ideas would have unknown side-effects, but they are worth testing in pilot studies.

The hard truth, however, is that the Arctic as it is known today is almost certainly gone. Efforts to mitigate global warming by cutting emissions remain essential. But the state of the Arctic shows that humans cannot simply undo climate change. They will have to adapt to it.