Archive for the ‘climate change – global warming’ Category

Climate change urgency: the Arctic is heating

April 2, 2018

Antarctic ice sheet loss and sea level rise Guardian[Excellent graphs]  1 March 2018 

dana1981 more https://www.theguardian.com/environment/climate-consensus-97-per-cent/2018/mar/01/decisions-today-will-decide-antarctic-ice-sheet-loss-and-sea-level-rise

A new study looks at how much global sea level will continue to rise even if we manage to meet the Paris climate target of staying below 2°C hotter than pre-industrial temperatures. The issue is that sea levels keep rising for several hundred years after we stabilize temperatures, largely due to the continued melting of ice sheets in Antarctica and Greenland from the heat already in the climate system.

The study considered two scenarios. In the first, human carbon pollution peaks somewhere between 2020 and 2035 and falls quickly thereafter, reaching zero between 2035 and 2055 and staying there. Global temperatures in the first scenario peak at and remain steady below 2°C. In the second scenario, we capture and sequester carbon to reach net negative emissions (more captured than emitted) between 2040 and 2060, resulting in falling global temperatures in the second half of the century.

The authors found that global average sea level will most likely rise by about 1.3 meters by 2300 in the first scenario, and by 1 meter in the second. However, there is large uncertaintydue to how little we understand about the stability of the large ice sheets in Greenland and especially Antarctica. At the high end of possible ice sheet loss, we could see as much as 4.5 meters of sea level rise by 2300 in the first scenario, and close to 3 meters in the second scenario.

The study also shows that it’s critical that our carbon pollution peaks soon. Each 5-year delay – a peak in 2025 instead of 2020, for example – most likely adds 20 cm of sea level rise by 2300, and could potentially add a full meter due to the uncertainty associated with the large ice sheets:

we find that a delay of global peak emissions by 5 years in scenarios compatible with the Paris Agreement results in around 20 cm of additional median sea-level rise in 2300 … we estimate that each 5 years of delay bear the risk of an additional 1 m of sea-level rise by 2300 … Delayed near-term mitigation action in the next decades will leave a substantial legacy for long-term sea-level rise.

And remember, this is all for scenarios in which we meet the Paris climate targets, which we’re currently not on pace to achieve. If we miss the Paris targets, sea levels will rise higher yet.

Another new study, published in the Proceedings of the National Academy of Sciences, found that sea level rise has been accelerating. If the rate of acceleration continues – which the lead author notes is a conservative estimate – we would see an additional 65 cm (close to a meter above pre-industrial sea level) of sea level rise by 2100.

Yet another new study published in The Cryosphere using satellite data found that while the East Antarctic Ice Sheet has remained stable in recent years, ice loss from the West Antarctic Ice Sheet has accelerated. Antarctica is now discharging 1.93 trillion tons of ice each year, up from about 1.89 trillion tons per year in 2008. When accounting for snow accumulation, the continent is losing about 183 billion tons of ice per year – enough to raise sea levels by about 3 to 5 millimeters per decade by itself. The melting of the Greenland Ice Sheet is likewise accelerating and is now responsible for about 25% of annual sea level rise (8.5 millimeters per decade).

Meanwhile, the Arctic has been remarkably warm in February – as much as 35°C hotter than average in some areas. In mid-winter, when sea ice should be growing, in the Bering Sea it’s instead shrinking.

The hot Arctic is important because the temperature difference between the Arctic and lower latitudes is one of the main forces that keeps the jet stream moving steadily west-to-east. With a hot Arctic, the jet stream is weakened, leading to weird weather in the USA and Europe. As a result, the western states have been experiencing relatively quite cold temperatures, while the US east coast has been unseasonably hot.

To sum up, ice sheet melt is accelerating, as in turn is sea level rise. Even if we manage to achieve the Paris target of less than 2°C global warming above pre-industrial temperatures, we’re likely to eventually see more than a meter of sea level rise, and potentially several meters. The longer we take to reach peak carbon pollution in the coming years, the higher the oceans will rise. Disappearing sea ice in the rapidly-warming Arctic also appears to be causing increasingly weird and extreme weather in places like America and Europe.

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Explaining Extreme Events from a Climate Perspective

April 2, 2018

American Meteorological Society, Dec 17, 

This BAMS special report presents assessments of how human-caused climate change may have affected the strength and likelihood of individual extreme events.

This sixth edition of explaining extreme events of the previous year (2016) from a climate perspective is the first of these reports to find that some extreme events were not possible in a preindustrial climate. The events were the 2016 record global heat, the heat across Asia, as well as a marine heat wave off the coast of Alaska. While these results are novel, they were not unexpected. Climate attribution scientists have been predicting that eventually the influence of human-caused climate change would become sufficiently strong as to push events beyond the bounds of natural variability alone. It was also predicted that we would first observe this phenomenon for heat events where the climate change influence is most pronounced. Additional retrospective analysis will reveal if, in fact, these are the first events of their kind or were simply some of the first to be discovered. Read More

DOWNLOAD EXPLAINING EXTREME EVENTS OF 2016
Download high resolution version (46 MB).  https://www.ametsoc.org/ams/index.cfm/publications/bulletin-of-the-american-meteorological-society-bams/explaining-extreme-events-from-a-climate-perspective/

United Nations Environment Emissions Gap Report 2017

April 2, 2018

Emissions Gap Report, http://www.unenvironment.org/resources/emissions-gap-report  [good graphs] , Authors: UN Environment, November 17 The goal of the Paris Agreement on climate change, as agreed at the Conference of the Parties in 2015, is to keep global temperature rise this century to well below 2 degrees Celsius above pre-industrial levels. It also calls for efforts to limit the temperature increase even further to 1.5 degrees Celsius.

The UN Environment Emissions Gap Report 2017 presents an assessment of current national mitigation efforts and the ambitions countries have presented in their Nationally Determined Contributions, which form the foundation of the Paris Agreement.

The report has been prepared by an international team of leading scientists, assessing all available information. The governments of countries mentioned specifically in the report have been invited to comment on the specific assessment findings; independent experts have also been invited to review the different chapters.

What’s new in this year’s report?

Update on global greenhouse gas emissions
This year, the Emissions Gap Report includes an assessment of the emissions associated with the Nationally Determined Contributions and current policies of each of the G20 members, including the European Union. This is in addition to presenting an update on global greenhouse gas emissions and national actions to meet the earlier Cancun pledges.

Exploring “negative emission technologies”
This year’s report explores removing carbon dioxide from the atmosphere as an additional way to mitigate climate change, over and above conventional abatement strategies.

An analysis of global carbon dioxide emissions from energy and industry

The Report includes a new systematic assessment of how various economic sectors can reduce their climate-warming emissions, focusing on the potential eductions from the wide application of already-known and cost-effective technologies.

The role of short-lived climate pollutants

The report describes the opportunities offered by limiting emissions of the so-called short-lived climate pollutants. Reductions of these pollutants will limit the rate of short-term warming, and when sustained and combined with reductions in carbon dioxide emissions, they help to limit long-term warming, which is the ultimate aim of closing the emissions gap.

Phasing out coal

This year’s report includes a detailed assessment of global developments in the coal sector. This also examines the options and barriers for a gradual coal phase-out.

In fact, nuclear power plants are a cause of climate change, generating Krypton-85

March 31, 2018
Krypton-85: How nuclear power plants cause climate change https://thesenecaeffect.wordpress.com/2015/07/01/krypton-85-how-nuclear-power-plants-cause-climate-change/

Nuclear power is often referred to as a low-carbon source of energy, implying that it would be a good idea to replace our fossil fuel based energy system with one based on nuclear energy. This is part of a dog and pony show, where the problem of climate change is reduced to its current main contributor, human carbon dioxide emissions. The problem with this approach is that replacing fossil fuel based energy with other energy sources is not a solution, if these other energy sources cause climate change through different mechanisms.

This brings us to the nuclear industry’s dirty little secret, known as Krypton-85. Natural processes generate small amounts of Krypton-85. This leads to an equilibrium concentration in the atmosphere of 0.009 PBq. However, nuclear power plants generate Krypton-85 as well. When spent fuel is recycled, Krypton-85 is released into the atmosphere. As a result, Krypton-85 concentrations in the atmosphere have risen dramatically. The concentration in 1973 was estimated at 1961 PBq. In 2000, the concentration was estimated at 4800 PBq, by 2009, this had increased to 5500 PBq.1

Why should we be interested in the Krypton-85 concentration in our atmosphere? Krypton-85 has a number of interesting effects. As a beta-emitter, Krypton-85 is capable of ionizing our atmosphere. This leads to the formation of ozone.2 In the stratosphere, we’re quite happy to witness the formation of ozone, as it protects us against harmful radiation from the sun. On the other hand, in the troposphere, the layer of the atmosphere beneath the stratosphere, the formation of ozone is a big problem. Unfortunately, Krypton-85’s ozone formation in the stratosphere is minor compared to that by cosmic rays.

In the troposphere on the other hand, Krypton-85 is believed to have a significant role in ozone formation compared to cosmic rays. This is especially significant at night, because normally ozone is not generated during the night, as it requires the presence of sunlight. Krypton-85 generates tropospheric ozone, during the day as well as during the night. Normally, Ozone concentrations in the troposphere drop to near zero during the night.3 In the presence of Krypton-85 however, ozone can be created at night as well.

What are the effect of this? Not a lot is known yet, unfortunately, despite the estimated eight orders of magnitude increase of ozone in our atmosphere. What is know about ozone however, reveals a cause of concern. Besides the fact that tropospheric ozone functions as a greenhouse gas, ozone damages plants. It is believed that ozone causes relatively more damage when trees are exposed to it at night, when concentrations are normally very low due to the absence of sunlight.4 Other worrisome effects of Krypton-85 are expected as well. In a 1994 study it was suggested that “there are unforeseeable effects for weather and climate if the krypton-85 content of the earth atmosphere continues to rise”.5 In its global atmosphere watch measurement guide, the World Meteorological Organization warned:

If 85Kr continues to increase, changes in such atmospheric processes and properties as atmospheric electric conductivity, ion current, the Earth’s magnetic field, formation of cloud condensation nuclei and aerosols, and frequency of lightning may result and thus disturb the Earth’s heat balance and precipitation patterns. These 85Kr-induced consequences call for 85Kr monitoring.6

Fortunately, there is good news as well. Thanks to the ongoing global phase-out of nuclear energy, global atmospheric Krypton-85 concentrations are estimated to have peaked back in 2009. If on the hand, a nuclear renaissance occurs after all, we could expect global atmospheric concentrations to continue to increase. It remains to be seen what the subsequent effects of this would be.


1 – http://www.sciencedirect.com/science/article/pii/S0265931X12001816?np=y

2 – Non-CO2 Greenhouse Gases: Why and How to Control? Proceedings of an International Symposium, Maastricht, The Netherlands, 13–15 December 1993

3 – http://earthobservatory.nasa.gov/Features/ChemistrySunlight/chemistry_sunlight2.php

4 – http://treephys.oxfordjournals.org/content/15/3/159.full.pdf

5 – http://www.opengrey.eu/item/display/10068/255704

6 – http://www.empa.ch/plugin/template/empa/*/7530

7 – http://dx.doi.org/10.1016/j.jenvrad.2012.07.006

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.

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.