Archive for the ‘climate change – global warming’ Category

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.

 
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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.

Arctic warm water is now being pushed to the surface

May 18, 2017
Climate change is literally turning the Arctic ocean inside out, WP,  April 6 There’s something special — and very counterintuitive — about the Arctic Ocean.

Unlike in the Atlantic or Pacific, where the water gets colder as it gets deeper, the Arctic is upside-down. The water gets warmer as it gets deeper. The reason is that warm, salty Atlantic-originating water that flows into the Arctic from the south is more dense, and so it nestles beneath a colder, fresher surface layer that is often capped by floating sea ice. This state of “stratification” makes the Arctic Ocean unique, and it means that waters don’t simply grow colder as you travel farther north — they also become inverted.

But in a paper in Science released Thursday, a team of Arctic scientists say this fundamental trait is now changing across a major part of the Arctic, in conjunction with a changing climate.

“I first went to the Arctic in about 1969, and I’ve never seen anything like this,” said Eddy Carmack, a researcher with Fisheries and Oceans Canada and one of the study’s authors. “Back then we just assumed the Arctic is as it is and it will be that way forevermore. So what we’re seeing in the last decade or so is quite remarkable.”

In a large area that they term the eastern Eurasian basin — north of the Laptev and East Siberian seas, which in turn are north of Siberia — the researchers found that warm Atlantic water is increasingly pushing to the surface and melting floating sea ice. This mixing, they say, has not only contributed to thinner ice and more areas of open water that used to be ice covered, but it also is changing the state of Arctic waters in a process the study terms “Atlantification” — and these characteristics could soon spread across more of the Arctic ocean, changing it fundamentally.

The study was led by Igor Polyakov of the University of Alaska at Fairbanks, in collaboration with a team of 15 researchers from the United States, Canada, Russia, Poland, Germany and Norway.

To understand the work, it’s important to first note the extensive and rapid shrinkage of Arctic sea ice of late in an area to the north of Siberia. The area, known as the eastern Eurasian basin, is seeing thinner ice and more months of open water. Arctic sea ice is a linchpin of the Earth’s climate system………https://www.washingtonpost.com/news/energy-environment/wp/2017/04/06/scientists-say-the-unique-arctic-ocean-is-being-transformed-before-our-eyes/?utm_campaign=crowdfire&utm_content=crowdfire&utm_medium=social&utm_source=twitter&utm_term=.40ec22cba221#350509998-tw#1491570060364

Climate change physics

May 18, 2017

Elevator Pitches – Chapter 02 – Radiative Gases Radiative Gases

A Musical Basis for Scattering Heat https://www.skepticalscience.com/ccep02.html24 March 2017 by Rob Honeycutt – This is another excerpt from my book 28 Climate Change Elevator Pitches. I’ll be publishing one chapter here on SkS each month.The scientific basis for understanding climate goes back to the 1820’s when brilliant French mathematician Joseph Fourier first proposed the idea that our planet’s atmosphere had heat-trapping properties. Fourier was trying to calculate what should be the temperature of a planet at our distance from the sun. He derived a figure about 33°C (59°F) colder than the actual average temperature of the Earth. For his figures to be correct, he thought gases in our atmosphere must have “radiative properties” with the capacity to absorb and re-emit heat energy. When visible sunlight passes through our atmosphere it warms the surface of the Earth. The heat that is emitted upward we refer to as infrared radiation, or IR. Infrared radiation is just another wavelength of energy which is invisible to the human eye, but we can feel that energy as heat. It’s this heat energy that is scattered by radiative gases in the atmosphere.

In the 1850’s a British scientist, John Tyndall, devised an apparatus enabling him to measure the heat absorbing properties of various gases. Earth’s atmosphere is composed primarily of nitrogen (78%) and oxygen (21%). The remaining 1 percent of gases are known as “trace gases.” Tyndall discovered that the radiative properties of nitrogen and oxygen are insignificant and transparent to infrared radiation (heat). But, he further discovered that some trace gases do efficiently block heat.

But, how does this work? Why would one gas be transparent to heat and another gas block it?

The most common radiative gases in our atmosphere are water (H2O), carbon dioxide(CO2), and to a lesser extent, methane (CH4), so let’s look at how these molecules are constructed. The first two have a single core atom with two other atoms attached to it. With H2O, there is a central oxygen atom with two hydrogen atoms attached. With CO2, there is a central carbon atom and two oxygen atoms attached. You can picture these being something like soap bubbles joined together, but imagine if you can, that these soap bubbles have an electromagnetic field incorporated into them. This electromagnetic field gently locks the molecule into a specific configuration. That magnetic field also allows the atoms to wobble around a bit as the molecule is floating about in the atmosphere. Methane is somewhat similarly constructed as CO2, but with a central carbon atom surrounded on four sides by hydrogen atoms making it a far more potent radiative gas than the others.

Infrared radiation is a wavelength of light. In a way, it’s analogous to sound waves traveling through the air. If you tap an A note tuning fork on your knee and then hold it against the soundboard of a guitar the A-string of the guitar will vibrate sympathetically. Infrared radiation also has a frequency range, so when visible sunlight (higher frequency energy) comes in and hits the surface of the planet, that energy warms the surface. The surface then emits lower frequency energy as heat (IR) back up through the atmosphere.

The capacity of these molecules to vibrate (the “wobbling”) is “tuned” like the guitar string and when infrared radiation in the right frequency interacts with these gases, the molecule vibrates sympathetically. What they’re doing is absorbing and re-emitting that IR heatenergy. The difference with the dominant molecules, like oxygen (O2) and nitrogen (N2), is they can’t vibrate in this same manner nor at the same frequency ranges, thus they are invisible to IR.

That is the fundamental physics of climate change: the vibrational modes of greenhouse gases acting to absorb and scatter heat energy in the atmosphere. This was a cutting-edge discovery of the mid-19th century but now an indisputable fact of science. Scientists have empirically measured, modeled, and applied these facts in numerous ways for well over a century.

Ocean acidification spreading rapidly in Arctic Ocean,

March 9, 2017

International team reports ocean acidification spreading rapidly in Arctic Ocean, EurekAlert, 28 Feb 17, UNIVERSITY OF DELAWARE  Ocean acidification (OA) is spreading rapidly in the western Arctic Ocean in both area and depth, according to new interdisciplinary research reported in Nature Climate Changeby a team of international collaborators, including University of Delaware professor Wei-Jun Cai.

The research shows that, between the 1990s and 2010, acidified waters expanded northward approximately 300 nautical miles from the Chukchi slope off the coast of northwestern Alaska to just below the North Pole. Also, the depth of acidified waters was found to have increased, from approximately 325 feet to over 800 feet (or from 100 to 250 meters).

“The Arctic Ocean is the first ocean where we see such a rapid and large-scale increase in acidification, at least twice as fast as that observed in the Pacific or Atlantic oceans,” said Cai, the U.S. lead principal investigator on the project and Mary A.S. Lighthipe Professor of Earth, Ocean, and Environment at UD.

“The rapid spread of ocean acidification in the western Arctic has implications for marine life, particularly clams, mussels and tiny sea snails that may have difficulty building or maintaining their shells in increasingly acidified waters,” said Richard Feely, NOAA senior scientist and a co-author of the research. Sea snails called pteropods are part of the Arctic food web and important to the diet of salmon and herring. Their decline could affect the larger marine ecosystem.

Among the Arctic species potentially at risk from ocean acidification are subsistence fisheries of shrimp and varieties of salmon and crab.

Other collaborators on the international project include Liqi Chen, the Chinese lead principal investigator and scientist with the Third Institute of Oceanography of State Oceanic Administration of China; and scientists at Xiamen University, China and the University of Gothenburg, Sweden, among other institutions…….

Arctic ocean ice melt in the summer, once found only in shallow waters of depths less than 650 feet or 200 meters, now spreads further into the Arctic Ocean.

“It’s like a melting pond floating on the Arctic Ocean. It’s a thin water mass that exchanges carbon dioxide rapidly with the atmosphere above, causing carbon dioxide and acidity to increase in the meltwater on top of the seawater,” said Cai. “When the ice forms in winter, acidified waters below the ice become dense and sink down into the water column, spreading into deeper waters.”https://www.eurekalert.org/pub_releases/2017-02/uod-itr022717.php

Possibility of drastic cooling in North Atlantic

March 9, 2017

Drastic cooling in North Atlantic beyond worst fears, scientists warn https://www.theguardian.com/environment/2017/feb/24/drastic-cooling-north-atlantic-beyond-worst-fears-scientists-warn

Climatologists say Labrador Sea could cool within a decade before end of this century, leading to unprecedented disruption, reports Climate News Network, Guardian,  , 25 Feb 17, For thousands of years, parts of northwest Europe have enjoyed a climate about 5C warmer than many other regions on the same latitude. But new scientific analysis suggests that that could change much sooner and much faster than thought possible.

Climatologists who have looked again at the possibility of major climate change in and around the Atlantic Ocean, a persistent puzzle to researchers, now say there is an almost 50% chance that a key area of the North Atlantic could cool suddenly and rapidly, within the space of a decade, before the end of this century.

That is a much starker prospect than even the worst-case scientific scenario proposed so far, which does not see the Atlantic ocean current shutdown happening for several hundred years at least.

A scenario even more drastic (but fortunately fictional) was the subject of the 2004 US movie The Day After Tomorrow, which portrayed the disruption of the North Atlantic’s circulation leading to global cooling and a new Ice Age.

To evaluate the risk of extreme climate change, researchers from the Environnements et Paléoenvironnements Océaniques et Continentaux laboratory (CNRS/University of Bordeaux, France), and the University of Southamptondeveloped an algorithm to analyse the 40 climate models considered by the Fifth Assessment Report.

The findings by the British and French team, published in the Nature Communications journal, in sharp contrast to the IPCC, put the probability of rapid North Atlantic cooling during this century at almost an even chance – nearly 50%.

Current climate models foresee a slowing of the meridional overturning circulation (MOC), sometimes known also as the thermohaline circulation, which is the phenomenon behind the more familiar Gulf Stream that carries warmth from Florida to European shores. If it did slow, that could lead to a dramatic, unprecedented disruption of the climate system.

In 2013, drawing on 40 climate change projections, the IPCC judged that this slowdown would occur gradually, over a long period. Its findings suggested that fast cooling of the North Atlantic during this century was unlikely.

But oceanographers from EU emBRACE had also re-examined the 40 projections by focusing on a critical spot in the northwest of the North Atlantic: the Labrador Sea.

The Labrador Sea is host to a convection system ultimately feeding into the ocean-wide MOC. The temperatures of its surface waters plummet in the winter, increasing their density and causing them to sink. This displaces deep waters, which bring their heat with them as they rise to the surface, preventing the formation of ice caps.

The algorithm developed by the Anglo-French researchers was able to detect quick sea surface temperature variations. With it they found that seven of the 40 climate models they were studying predicted a total shutdown of convection, leading to abrupt cooling of the Labrador Sea by 2C to 3C over less than 10 years. This in turn would drastically lower North Atlantic coastal temperatures.

But because only a handful of the models supported this projection, the researchers focused on the critical parameter triggering winter convection: ocean stratification. Five of the models that included stratification predicted a rapid drop in North Atlantic temperatures.

The researchers say these projections can one day be tested against real data from the international OSnap project, whose teams will be anchoring scientific instruments within the sub-polar gyre (a gyre is any large system of circulating ocean currents).

If the predictions are borne out and the North Atlantic waters do cool rapidly over the coming years, the team says, with considerable understatement, climate change adaptation policies for regions bordering the North Atlantic will have to take account of this phenomenon.

NASA project – Oceans Melting Greenland (OMG) studies future sea level rise

March 9, 2017

OMG measurements of Greenland give us a glimpse of future sea rise https://www.skepticalscience.com/omg-greenland-sea-level-rise.html 24 February 2017 by John Abraham  If you meet a group of climate scientists, and ask them how much sea levels will rise by say the year 2100, you will get a wide range of answers. But, those with most expertise in sea level rise will tell you perhaps 1 meter (a little over three feet). Then, they will immediately say, “but there is a lot of uncertainty on this estimate.” It doesn’t mean they aren’t certain there will be sea level rise – that is guaranteed as we add more heat in the oceans. Here, uncertainty means it could be a lot more or a little less.

Why are scientists not certain about how much the sea level will rise? Because there are processes that are occurring that have the potential for causing huge sea level rise, but we’re uncertain about how fast they will occur. Specifically, two very large sheets of ice sit atop Greenland and Antarctica. If those sheets melt, sea levels will rise hundreds of feet.

Parts of the ice sheets are melting, but how much will melt and how fast will the melting occur? Are we talking decades? Centuries? Millennia? Scientists really want to know the answer to this question. Not only is it interesting scientifically, but it has huge impacts on coastal planning.

One reason the answer to this question is illusive is that melting of ice sheets can occur from above (warm air and sunlight) or from below (warm ocean waters). In many instances, it’s the melting from below that is most significant – but this melting from below is really hard to measure.

With hope we will have a much clearer sense of ice sheet melting and sea level rise because of a new scientific endeavor that is part of a NASA project – Oceans Melting Greenland (OMG). This project has brought together some of the best oceanographers and ice experts in the world. The preliminary results are encouraging and are discussed in two recent publications here and here.

In the papers, the authors note that Greenland ice loss has increased substantially in recent decades. It now contributes approximately 1/3 to total sea level rise. The authors want to know whether this contribution will change over time and they recognize that underwater processes may be the most important to study. In fact, they note in their paper:

Specifically, our goal is improved understanding of how ocean hydrographic variability around the ice sheet impacts glacial melt rates, thinning and retreat.

In plain English, they want to know how water flow around Greenland affects the ice melt.

Their experiments are measuring a number of key attributes. First, yearly changes in the temperature of ocean water near Greenland. Second, the yearly changes to the glaciers on Greenland that extend into the ocean waters. Third, they are observing marine topography (the shape of the land underneath the ocean surface).

The sea floor shape is quite complicated, particularly near Greenland. Past glaciers carved deep troughs in the sea floor in some areas, allowing warm salty water to reach huge glaciers that are draining the ice sheet. As lead OMG investigator Josh Willis said:

What’s interesting about the waters around Greenland is that they are upside down. Warm, salty water, which is heavy, sits below a layer of cold, fresh water from the Arctic Ocean. That means the warm water is down deep, and glaciers sitting in deep water could be in trouble.

As the warm water attacks marine glaciers (glaciers that extend into the ocean), the ice tends to break and calve, retreating toward land. In some cases, the glaciers retreat until their grounding line coincides with the shore. But in other cases the undulating surface allows warm water to wear the glacier underside for long distances and thereby increase the risk of large calving events.

Oftentimes, when glaciers near the coast break off they uncork other ice that can then more easily flow into the oceans.

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