Climate change: ‘human fingerprint’ found on global extreme weather

Global warming makes temperature patterns that cause heatwaves, droughts and floods across Europe, north America and Asia more likely, scientists find.

The fingerprint of human-caused climate change has been found on heatwaves, droughts and floods across the world, according to scientists.

The discovery indicates that the impacts of global warming are already being felt by society and adds further urgency to the need to cut carbon emissions. A key factor is the fast-melting Arctic, which is now strongly linked to extreme weather across Europe, Asia and north America.

Rising greenhouse gases in the atmosphere have long been expected to lead to increasing extreme weather events, as they trap extra energy in the atmosphere. But linking global warming to particular events is difficult because the climate is naturally variable.

The new work analysed a type of extreme weather event known to be caused by changes in “planetary waves” – such as California’s ongoing record drought, and recent heatwaves in the US and Russia, as well as severe floods in Pakistan in 2010.

Planetary waves are a pattern of winds, of which the jet stream is a part, that encircle the northern hemisphere in lines that undulate from the tropics to the poles. Normally, the whole wave moves eastwards but, under certain temperature conditions, the wave can halt its movement. This leaves whole regions under the same weather for extended periods, which can turn hot spells into heatwaves and wet weather into floods.

This type of extreme weather event is known to have increased in recent decades. But the new research used observations and climate models to show that the chances of the conditions needed to halt the planetary waves occurring are significantly more likely as a result of global warming.

“Human activity has been suspected of contributing to this pattern before, but now we uncover a clear fingerprint of human activity,” said Prof Michael Mann, at Pennsylvania State University in the US and who led the study published in the journal Scientific Reports.

Large scale wind patterns are largely driven by the temperature difference between the poles and the tropics. But global warming is altering this difference because the Arctic is heating up faster than lower latitudes and because land areas are heating up faster than the oceans.

Recent changes in the Arctic are particularly striking, with record low levels of ice cover and extremely unusual high temperatures. “Things in the Arctic are happening much faster than we expected,” said Prof Stefan Rahmstorf, also at PIK.

“It is not just a problem of nature conservation or polar bears, it is about a threat to human society that comes from these rapid changes,” he said. “This is because it hits us with increasing extreme events in the highly populated centres in the mid-latitudes. It also affects us through sea level rise, which is hitting shores globally. So these changes that are going on in the Arctic should concern everyone.”

Other climate research, called attribution, is increasingly able to calculate how much more likely specific extreme weather events have been made by global warming. For example, the heatwave in south-eastern Australia in February was made twice as likely by climate change, while Storm Desmond, which caused heavy flooding in the UK in 2015, was made 40% more likely.

Trump to sign order sweeping away Obama-era climate policies

U.S. President Donald Trump will sign an executive order on Tuesday to undo a slew of Obama-era climate change regulations that his administration says is hobbling oil drillers and coal miners, a move environmental groups have vowed to take to court.

The decree's main target is former President Barack Obama's Clean Power Plan, requiring states to slash carbon emissions from power plants - a critical element in helping the United States meet its commitments to a global climate change accord reached by nearly 200 countries in Paris in 2015.

The so-called "Energy Independence" order will also reverse a ban on coal leasing on federal lands, undo rules to curb methane emissions from oil and gas production, and reduce the weight of climate change and carbon emissions in policy and infrastructure permitting decisions.

"We're going to go in a different direction," a senior White House official told reporters ahead of Tuesday's order. "The previous administration devalued workers with their policies. We can protect the environment while providing people with work."

The wide-ranging order is the boldest yet in Trump’s broader push to cut environmental regulation to revive the drilling and mining industries, a promise he made repeatedly during the presidential campaign. But energy analysts and executives have questioned whether the moves will have a big effect on their industries, and environmentalists have called them reckless.

"I cannot tell you how many jobs the executive order is going to create but I can tell you that it provides confidence in this administration’s commitment to the coal industry," Kentucky Coal Association president Tyler White told Reuters.

Trump will sign the order at the Environmental Protection Agency with Administrator Scott Pruitt, Interior Secretary Ryan Zinke and Energy Secretary Rick Perry on Tuesday afternoon.

U.S. presidents have aimed to reduce U.S. dependence on foreign oil since the Arab oil embargo of the 1970s, which triggered soaring prices. But the United States still imports about 7.9 million barrels of crude oil a day, almost enough meet total oil demand in Japan and India combined.

'ASSAULT ON AMERICAN VALUES'

Environmental groups hurled scorn on Trump's order, arguing it is dangerous and goes against the broader global trend toward cleaner energy technologies.

"These actions are an assault on American values and they endanger the health, safety and prosperity of every American," said billionaire environmental activist Tom Steyer, the head of activist group NextGen Climate.

Green group Earthjustice was one of many organizations that said it will fight the order both in and out of court. "This order ignores the law and scientific reality," said its president, Trip Van Noppen.

An overwhelming majority of scientists believe that human use of oil and coal for energy is a main driver of climate change, causing a damaging rise in sea levels, droughts, and more frequent violent storms.

Trump and several members of his administration, however, have doubts about climate change, and Trump promised during his campaign to pull the United States out of the Paris climate accord, arguing it would hurt U.S. business.

Since being elected Trump has been mum on the Paris deal and the executive order does not address it.

Christiana Figueres, former executive secretary of the United Nations Framework Convention on Climate Change who helped broker the Paris accord, lamented Trump's order.

"Trying to make fossil fuels remain competitive in the face of a booming clean renewable power sector, with the clean air and plentiful jobs it continues to generate, is going against the flow of economics," she said.

The order will direct the EPA to start a formal "review" process to undo the Clean Power Plan, which was introduced by Obama in 2014 but was never implemented in part because of legal challenges brought by Republican-controlled states.

The Clean Power Plan required states to collectively cut carbon emissions from power plants by 32 percent below 2005 levels by 2030.

Trump’s order lifts the Interior Department's Bureau of Land Management's temporary ban on coal leasing on federal property put in place by Obama in 2016 as part of a review to study the program's impact on climate change and ensure royalty revenues were fair to taxpayers.

It also asks federal agencies to discount the cost of carbon in policy decisions and the weight of climate change considerations in infrastructure permitting, and reverses rules limiting methane leakage from oil and gas facilities.

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Global warming: Humans responsible for 60% loss of sea ice, study shows

That human activity is a cause of global warming and changing temperatures is a fact that cannot be debated, but until now, scientists had little clue as to what was the extent of damage due to human intervention.

That human activity is a cause of global warming and changing temperatures is a fact that cannot be debated, but until now, scientists had little clue as to what was the extent of damage due to human intervention. A paper published in Nature, based on model simulations of different climate conditions, shows that humans may be responsible for 50-70% change in climate conditions, leading to melting of ice at the Arctic sea. Although the study absolved humans for air flow changes, 70% of which, it said, is due to natural variability, it pointed that 60% of sea ice decline since 1979 was caused by summer-time changes in atmospheric circulation.

While the study is expected to change how we observe climate change, it will also get us to alter our future predictions. With Arctic ice depleting fast—in January it was 1.26 million square kilometres, which was 8.6% below the 1981–2010 average—global warming would need coordinated action from governments. Policy turns in the US—Republicans have presented a bill in the Congress to do away with the country’s Environmental Protection Agency—will end up harming the environment. With global warming accompanying industrialisation, countries would need a concerted approach to tackle its ill-effects.

Arctic circle could become completely free of sea ice even if global warming limited to two degrees Celsius

Loss of sea ice could have 'catastrophic' effects on the weather in much of the northern hemisphere and speed up global warming.

The Arctic Ocean could become free of sea ice for the first time in 100,000 years even if action is taken to keep global warming to within two degrees Celsius, scientists have warned.

The region has experienced much sharper rises in temperature in recent decades that the rest of the world with temperatures in winter in Spitsbergen an astonishing 8 to 11C higher than the average between 1961 and 1990.

And this is believed to be having a significant effect on the weather in much of the northern hemisphere, increasing the number of dangerous storms. One leading expert has warned it could have a “catastrophic” effect on the Earth’s climate.

The loss of sea ice, which reflects much of the energy from sunlight, will also increase the rate of global warming.

In a paper in the journal Nature Climate Change, Dr James Screen and Dr Daniel Williamson, of Exeter University, looked at the likelihood of the ice disappearing almost completely if temperatures rose by 1.5C or 2C.

The Paris Agreement on climate change spoke of keeping global warming below 2C and as close to 1.5C as possible – in order to avoid levels considered particularly dangerous – but the world is currently on track to hit anything from 2.6C to 3.1C by the end of the century.

The researchers wrote: “We estimate there is less than a one-in-100,000 chance of an ice-free Arctic if global warming stays below 1.5C, and around a one-in-three chance if global warming is limited to 2C. 

“We suppose then that a summer ice-free Arctic is virtually certain to be avoided if the 1.5C target of the Paris Agreement is met. 

“However, the 2C target may be insufficient to prevent an ice-free Arctic.”

The Arctic will be considered ice-free if it falls to below a million square kilometres. This would mean the sea around the North Pole would be clear with the remaining ice found mainly in the small islands and inlets off the north coasts of Russia and Canada, where the effect of the land, which gets colder than the sea, is more pronounced.

In September last year, Arctic sea ice fell to about 4.1 million square kilometres, the second lowest figure, compared to about 3.4 million in 2012, according to the US National Snow & Ice Data Centre.

Antarctic sea ice is currently at record low levels with 2.14 million square kilometres, compared to the average of 3.16 million between 1981 and 2010.

In December, the US National Oceanic and Atmospheric Administration (NOAA) said the situation was changing so quickly it was “outpacing our ability to understand and explain” what was happening.

They suggested the word “glacial” should not be used to mean something happening slowly but as a term for something that was “rapidly diminishing”.

New Study Shows No Global Warming Pause

UNITED STATES—There has not been a pause in global warming according to newly published findings. A new study in the journal “Science Advances” back an earlier NOAA study that came to similar conclusions.

According to The Washington Post, a 2015 NOAA study contradicted an argument questioning the scientific consensus on climate change.

“The skeptics had for years suggested that following the then-record warm year of 1998 and throughout the beginning of the 21st century, global warming had slowed down or ‘paused,’” the article states. “But the 2015 paper, led by NOAA’s Thomas Karl, employed an update to the agency’s influential temperature dataset, and in particular to its record of the planet’s ocean temperatures, to suggest that really, the recent period was perfectly consistent with the much longer warming trend.”

The article goes on to explain that the study caused controversy in Congress.

“It actually led to a congressional subpoena from Rep. Lamar Smith, chair of the House Committee on Science, who charged that ‘NOAA’s decision to readjust historical temperature records has broad national implications’ and requested more information on why NOAA had made the dataset adjustment, including data and communications from the scientists involved,” the article says.

A new study published on January 4 supports the findings of the earlier NOAA study. The study’s lead authors, Kevin Cowtan and Zeke Hausfather, wrote a blog post for Scientific American on their study and the political controversy around the older NOAA findings.

“Our results suggests that the new NOAA record is likely the most accurate of the various sea surface temperature records during the past two decades, and should help resolve some of the criticism that accompanied the original NOAA study,” the Washington Post said.

“However the scientific question of how fast the Earth has been warming over the past two decades can be answered by replication from the scientific community, not by a political investigation. And the best evidence we have says that NOAA got it right,” the post says.

The new study can be found here.

Antarctica found amplifying effects of climate change during last global warming

SAN FRANCISCO -- A a new study indicates that the Antarctic warmed about 11 degrees Celsius between about 20,000 and 10,000 years ago while the average temperature worldwide rose about 4 degrees Celsius following Earth's last ice age.

The disparity, that the Antarctic warmed nearly three times the average temperature increase worldwide after the peak of last ice age 20,000 years ago, highlights the fact that the poles, both the Arctic in the north and the Antarctic in the south, amplify the effects of a changing climate, whether it gets warmer or cooler.

As the calculations are in line with estimates from most climate models,"the result is not a surprise, but if you look at the global climate models that have been used to analyze what the planet looked like 20,000 years ago, the same models used to predict global warming in the future, they are doing, on average, a very good job reproducing how cold it was in Antarctica," said Kurt Cuffey, a glaciologist at the University of California, Berkeley.

The models predict that as a result of current global climate change, Antarctica will warm twice as much as the rest of the planet and reach its peak in a couple of hundred years. Given business-as-usual greenhouse gas emissions, a global average increase of 3 degrees Celsius by 2100 and a rise of around 6 degrees in the Antarctic is predicted.

During the last period of global warming, the ice deep inside the Antarctic glaciers warmed more slowly than Earth's surface. By measuring the remaining difference, that the 20,000-year old ice deep in the West Antarctic ice sheet is about 1 degree Celsius cooler than the surface, the researchers were able to estimate the original temperature based on how fast pure ice warms up.

Gary Clow of the U.S. Geological Survey in Lakewood, Colorado, measured in 2011 and again in 2014 the temperature in a 3.4-kilometer-deep borehole from which the West Antarctic Sheet Divide ice core had been drilled during an eight-year project that ended in 2011. Ice at the bottom of the borehole was deposited about 70,000 years ago; ice about one-sixth of the way up about 50,000 years ago; and ice about one-third of the way to the surface 20,000 years ago.

Cuffey, first author of the study recently published in the Proceedings of the National Academy of Sciences, developed a technique to combine these temperature measurements with isotopic measurements of old ice to come up with an estimated temperature of 11.3 degrees, plus or minus 1.8 degrees Celsius, warming since the depths of the ice age.

The Antarctic temperature rose much more rapidly than did Arctic temperatures after the glacial maximum. By 15,000 years ago, Antarctica had warmed to about 75 percent of its temperature today. The Arctic took another 3,000-4,000 years to warm this much, primarily because the Northern Hemisphere had huge ice sheets to buffer warming, and changes in ocean currents and Earth's orbital configuration accelerated warming in the south.

Antarctica was also more sensitive to global carbon dioxide levels, Cuffey was quoted as saying in a news release from UC Berkeley, adding that the situation today, with global warming driven primarily by human emissions of carbon dioxide from burning fossil fuels, is different from natural cycles. The ability of the oceans to take up carbon dioxide cannot keep up with the rising levels of greenhouse gases in the atmosphere, meaning carbon dioxide and global temperatures will continue to increase unless humans cut their emissions.

2016 'very likely' to be world's warmest year

2016 looks poised to be the warmest year on record globally, according to preliminary data.

With data from just the first nine months, scientists are 90% certain that 2016 will pass the mark set by 2015.

Temperatures from January to September were 1.2C above pre-industrial levels, according to the World Meteorological Organization (WMO).

The body says temperatures should remain high enough for the rest of the year to break the previous record.

El Nino has had an impact, but the most significant factor driving temperatures up continues to be CO2 emissions.

What is climate change?

The provisional statement on the status of the global climate in 2016 has been released early this year to help inform negotiators meeting in Morocco, who are trying to push forward with the Paris Climate Agreement.

The document says the year to September was 0.88 above the average for the period between 1961-90, which the WMO uses at its baseline.

The whole of 2015, which broke the previous record by a significant amount, was 0.77 above the 1961-90 average.

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While there are still a couple of months to go this year, a preliminary analysis of the October data indicates that 2016 is very much on track to surpass the 2015 level, which in turn broke the previous high mark set in 2014.

"Another year. Another record. The high temperatures we saw in 2015 are set to be beaten in 2016," said WMO secretary-general Petteri Taalas.

"In parts of Arctic Russia, temperatures were 6C to 7C above the long-term average. Many other Arctic and sub-Arctic regions in Russia, Alaska and north-west Canada were at least 3C above average. We are used to measuring temperature records in fractions of a degree, and so this is different," said Mr Taalas.

The report highlights the fact that other long-term climate change indicators are also breaking records. The amount of greenhouse gas in the atmosphere continued on its upward march in 2016.

Arctic sea ice continued to melt in significant amounts, while the Greenland ice sheet displayed very early melting this year.

Experts believe that the El Nino weather phenomenon played a role in the record warm temperatures seen in 2015 and 2016.

They quantify it as roughly 0.2 of a degree - but the bulk of the warming is coming from the accumulation of greenhouse gases. And the impacts of that warming are being widely felt.

"Because of climate change, the occurrence and impact of extreme events has risen," said Petteri Taalas.

"'Once in a generation' heatwaves and flooding are becoming more regular. Sea level rise has increased exposure to storm surges associated with tropical cyclones," he said.

The surprise election of Donald Trump as president of the US has increased expectations that he will bring a more sceptical view of climate change to the White House.

Scientists are stressing that the evidence for the reality of climate change is getting stronger all the time.

"We are seeing the impacts of climate change on extreme weather," said Dr Peter Stott, who leads the climate attribution team at the UK Met Office.

"One degree may sound a relatively small number but in the context of such a stable climate that we've had over the past millennia, and the rapidity of that warming, we are seeing this real world evidence that doesn't come from a model or a projection."

According to the WMO analysis, 16 of the 17 warmest years have been recorded this century. The only exception was 1998.

 

Least Developed Countries Call for 'Ambitious Action' at COP22

Achieving the crucial 1.5°C target will require immediately halting new fossil fuel development now.

The chair of the Least Developed Countries group, Tosi Mpanu-Mpanu, called for “fair and ambitious action” Monday at the next round of international climate change negotiations which begin on Nov. 7 in Marrakech, Morocco.

Mpanu-Mpanu, senior negotiator for the Democratic Republic of Congo on climate issues, said that the next round of UN climate talks, COP22, must be “an action and implementation COP” and must “construct robust rules to support the [Paris] Agreement's implementation.”

ANALYSIS: 5 Ways the COP21 Deal Dooms the Planet to Climate Change Chaos

Mpanu-Mpanu expressed his concern that even with a full implementation of the Paris Agreement, which comes officially into force on Nov. 4, current pledges by countries to cut greenhouse gas emissions puts the world on track for 3-3.5°C of warming above pre-industrial levels.

“Science tells us that beyond temperature increases of 1.5°C the future of our planet stands on increasingly thin ice. We cannot afford to treat this as an aspirational goal,” he said.

According to Payal Parekh, program director at climate action group 350.org, achieving the crucial 1.5°C target will require immediately halting new fossil fuel development now. “Around the world, there is a powerful and growing fossil fuel resistance movement that is pushing our institutions and governments to divest and break free from fossil fuels to prioritize people and the planet,” added Parekh.

RELATED: Activists Shut 5 Canada-US Pipelines to Support Standing Rock

With this goal in mind the LDC group plans to launch their Renewable Energy and Energy Efficiency Initiative for Sustainable Development at the UN conference. Mpanu-Mpanu said the plan “demonstrates the continued commitment of the LDC group to real solutions that benefit real people on the ground.”

The Initiative, according to Mpanu-Mpanu, will enable LDCs to leapfrog fossil fuel based energy and generate prosperity by bringing “modern, clean, resilient energy systems to millions of energy-starved people."

The LDC group is made up of 48 primarily African nations that are especially vulnerable to climate change but have done the least to cause the problem. They came together to demand that wealthier nations act in accordance with their responsibility for creating the climate problem and their capability for addressing it.

The talks in Morocco take place in the midst of massive protests over the recent killing of a fish seller in the coastal community of Al Hoceima which has been hard hit by severe government restrictions on small-scale fishermen in response to declining fish populations linked to climate change.

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