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Explaining climate change science & rebutting global warming misinformation

Scientific skepticism is healthy. Scientists should always challenge themselves to improve their understanding. Yet this isn't what happens with climate change denial. Skeptics vigorously criticise any evidence that supports man-made global warming and yet embrace any argument, op-ed, blog or study that purports to refute global warming. This website gets skeptical about global warming skepticism. Do their arguments have any scientific basis? What does the peer reviewed scientific literature say?

 


More evidence that global warming is intensifying extreme weather

Posted on 4 July 2015 by John Abraham

Just this week, a new article appeared in the journal Nature that provides more evidence of a connection between extreme weather and global warming. This falls on the heels of last week’s article which made a similar connection. So, what is new with the second paper? A lot.

Extreme weather can be exacerbated by global warming either because the currents of atmosphere and oceans change, or it can be exacerbated through thermodynamics (the interaction of heat, energy, moisture, etc.). Last week’s study dealt with just the thermodynamics. This week’s study presents a method to deal with both.

The authors, Daniel HortonNoah Diffenbaugh and colleagues used a new technique to tease apart the complex influences of warming on changes to atmospheric circulation. Dr. Horton told me,

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0 comments


New study warns of dangerous climate change risks to the Earth’s oceans

Posted on 2 July 2015 by dana1981

A new paper just published in Science summarizes the projected impacts of climate change on the world’s oceans, and consequently on humans and our economy. The study concludes that global warming beyond the international limit of 2°C above pre-industrial temperatures would pose serious threats to marine ecosystems and their millions of human dependents. It builds on the consensus science published by the Intergovernmental Panel on Climate Change last year. The study concludes,

Ocean changes associated with a 2°C warming of global surface temperature carries high risks of impacts and should not be exceeded.

Gattuso

Regional changes in the physical system and associated risks for natural and human-managed systems. Source: Science; Gattuso et al. (2015) modified from IPCC WGII AR5 (2014).

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1 comments


2015 SkS News Bulletin #6: Pope Francis & Climate Change

Posted on 2 July 2015 by John Hartz

Coal-state lawmakers attack climate rule no matter what pope says

Pope Francis’ call for urgent action to combat climate change isn’t having much influence on members of Congress from the coal state of Kentucky, who are working this week to block the centerpiece of the president’s agenda to limit the greenhouse gases that are warming the planet.

The House of Representatives is expected as soon as Wednesday to pass a bill by Rep. Ed Whitfield, R-Ky., which would allow states to reject the Environmental Protection Agency’s proposed rule for carbon emissions from power plants. Whitfield’s bill also would ban the EPA from enforcing the rule until all the legal challenges are decided, which could take years.

There’s a similar effort in the Senate. Senate Majority Leader Mitch McConnell, R-Ky., is calling on states to defy the Obama administration’s climate rule. He put language in the interior and environment spending bill that would allow them to do so without consequences, saying the Obama administration is at war “against Kentucky coal jobs, miners and their families.”

Coal-state lawmakers attack climate rule no matter what pope says by Sean Cockerham, McClatchy Washington Bureau, June 23, 2015


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2 comments


2015 SkS Weekly News Roundup #27A

Posted on 1 July 2015 by John Hartz

Barack Obama turns tables in David Attenborough climate change interview

Barack Obama was the one asking the questions in an interview with British naturalist David Attenborough that aired on Sunday in which they agreed that combating climate change would require a global effort.

Saying he had long been a “huge admirer” of Attenborough’s TV documentaries about the environment, Obama turned the tables on Attenborough in an interview taped on 8 May at the White House, which aired on the BBC and other international broadcasters. 

Barack Obama turns tables in David Attenborough climate change interview Reuters/Guardian, June 28, 2015


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As the Denial101x course ends, a new one begins

Posted on 1 July 2015 by BaerbelW

On June 16, the first iteration of Denial101x came to a close and here is a collection of feedback from students, lecturers and course staff to hopefully whet your appetite to enroll in the self-paced version of our MOOC due to launch on July 1!

Student perspective

Thousands of students from around the world participated in Denial101x and many of them put a pin on a map:

Denial101x-Map

We received videos from students across the world sharing their experience with and perspective about Denial101. Here is a compilation of them:

Lecturer perspective

Dr. Keah Schuenemann - one of our MOOC's lecturers - published a blog-post about her experience. It starts with the students' video feedback followed by this :

It really makes me feel like all of the hard work was worth it!  I spent most weekends this semester working on this course.  Plus, I made a lot of new friends that I hope to continue to work with in the future.  Thanks to John Cook for inviting me to participate!

Keah also created a playlist containing all her lectures: Heat Waves, Wavy Jet Stream, Sea Level Rise, Extreme Weather, Weather vs Climate models, Water Vapor Amplifies Warming, and IPCC Underestimates:

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3 comments


A Southern Hemisphere Booster of Super El Niño

Posted on 30 June 2015 by Rob Painting

Key Points:
  • Hong et al (2014) looked at global observations and model simulations to find out what sets a super El Niño apart. They discovered that a prerequisite condition was a circulation in the Southern Hemisphere, associated with a persistent high pressure system situated over Southern Australia and a low pressure system in the South Pacific, that fed surface winds back to the equator and therefore boosted anomalous westerly winds along the equator between the critical June to November development stage.

Figure 1 - Anomalous sea level pressure (colours) and surface winds (black arrows) for June-November for the 3 Super El Niño identified in the observational record. The strong equatorward wind flow around the edge of the Australian high pressure system feeds into and augments the anomalous westerly wind flowing along the equator - boosting super El Niño development. These large-scale features are absent from standard El Niño events. Image adapted from Hong et al (2014)

El Niño on my mind

The largest year-to-year variation in global weather results from the El Niño-Southern Oscillation (ENSO). At one extreme we have La Niña, a time when the normal easterly trade winds in the tropics intensify, and at the other extreme we have El Niño, a time when the trade winds weaken or even reverse. These winds are important because their persistence effects change, albeit temporary in this case, in the large-scale circulation of the ocean and atmosphere.

The near-permanent nature of the easterly tropical trade winds are largely a consequence of the strong warming of the ocean at the equator and Earth's rapid rate of rotation. Intense solar heating of the Pacific ocean drives strong evaporative uplift and cooler air near the surface moves into replace the vertically displaced warm air. As it does so, the incoming air is 'steered' toward the west by the Coriolis force (to its right in the Northern Hemisphere, and toward its left in the Southern Hemisphere). This really isn't a force in the strictest sense, but a useful mathematical construct to understand motion in a rotational frame of reference. In reality, due to its rotation, the Earth beneath is moving at a different speed to the loosely gravitationally-bound air above it.  

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6 comments


Irreversible loss of world's ice cover should spur leaders into action, say scientists

Posted on 29 June 2015 by Guest Author

This is a re-post from Carbon Brief by Roz Pidcock

We need only look to the world's ice cover to see the urgency with which emissions need to come down, scientists told delegates at this week's climate talks in Bonn, Germany.

At a press conference today, US and German scientists updated negotiators and journalists with the latest science on the state of Arctic sea ice, the Antarctic continent and thawing permafrost.

New observations gathered since the Intergovernmental Panel on Climate Change (IPCC) report show the cryosphere in serious and irreversible decline, they warned.

Pam Pearson, director of the International Cryosphere Climate Initiative, the network of policy experts and researchers holding the event, told the audience:

"This is not like air pollution or water pollution, where if you clean it up it will go back to the way it was before."

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3 comments


2015 SkS Weekly Digest #26

Posted on 28 June 2015 by John Hartz

SkS Highlights

New study links global warming to Hurricane Sandy and other extreme weather events by John Abraham garnered the most commen ts of the articles posted on SkS during the past week.  The Carbon Brief Interview: Christiana Figueres by Leo Hickman (The Carbon Brief) attracted the second highest number and Cracking the mystery of the corrosive ocean by Kaitlin Alexander (ClimateSight) received the the third highest.

El Niño Watch

The El Niño event increasing storm potential in the Pacific Ocean is likely to disrupt oil shipments around the globe, spelling higher gas prices at the pump and rising costs at the grocery store.

Commodities traders are already factoring in a rise in oil prices, according to the Financial Times. That's because any interruption in shipping routes is a major cost on transportation. And when the cargo being shipped is oil, food and consumer goods are also likely to see inflated prices.

U.S. oil imports ship largely from the Middle East around the Cape of Good Hope in Africa and across the Atlantic. The Atlantic hurricane season this year is expected to be calmer than normal, so imports won't likely be constrained.

El Nino may spell higher prices at pump, grocery store by Thomas M. Kostigen, USA Today, June 27, 2015 

Toon of the Week

 2015 SkS Toon 26

On climate change, will Christians follow Pope Francis or Rush Limbaugh? by David Horsey, Los Angeles Times, June 25, 2015

Hat tip to I Heart Climate Scientists

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2015 SkS Weekly News Roundup #26B

Posted on 28 June 2015 by John Hartz

Alaska’s glaciers seen as major source of sea level rise

The ice that tumbles into the ocean along Alaska’s coastline often makes for dramatic images that show one of the ravages of climate change – melting tidewater glaciers that contribute to sea level rise. But a new study finds that far more meltwater is flowing into the sea from a similar, if less frequently photographed source – inland glaciers.

Compared to their coastal counterparts, inland glaciers account for 95 percent of glacial mass loss due to climate-driven melting, a study published this month in Geophysical Research Letters shows. In fact, researchers found that Alaska’s glaciers are melting so fast that they would cover the state with a 1-foot thick layer of water every seven years.

“This is the first time that we’ve assessed all of the glaciers and been able to say how much of the total is coming from tidewater glaciers, and here’s how much of the total is from lake and land glaciers,” Shad O’Neel, a University of Alaska Fairbanks researcher and co-author of the study, said.

Alaska’s glaciers seen as major source of sea level rise by Chelsey B. Coombs , Climate Central, June 25.


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9 comments


2015 SkS Weekly News Roundup #26A

Posted on 27 June 2015 by John Hartz

6 devastating heat waves hitting the planet

Need proof that we’re having the hottest year on record? Scorching heat is searing parts of the world, sparking wildfires and claiming lives due to heat stroke and dehydration.

6 Devastating Heat Waves Hitting the Planet by Lorraine Chow, EcoWatch, June 23, 2015


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Why warmer storms could lead to more flooding than expected

Posted on 26 June 2015 by Guest Author

By The ConversationConrad Wasko, UNSW Australia and Ashish Sharma, UNSW Australia

As the climate changes, we can expect more frequent and more extreme weather events, which will put pressure on our current infrastructure. It has been suggested that increasing temperatures will intensify rainfall, indicating that we are likely to endure bigger storms and more dangerous flooding in a future warmer climate.

Our study, published in the journal Nature Geoscience, shows that this intensification in flooding may be even greater than expected. This is because of changes to the distribution of rainfall within storms – something known as the “temporal pattern”.

This study is the first to show that temperature changes are disrupting temporal rainfall patterns within storms themselves. When it comes to flash flooding, this is just as important, if not more so, than the total volume of rainfall that a given storm delivers.

If this trend continues with future climate warming, more destructive flooding across Australia’s major urban centres is likely. Because our findings were true across every Australian climate zone, ranging from tropical and arid to temperate, we can expect similar risks throughout the country, and conceivably elsewhere in the world too.

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Cracking the mystery of the corrosive ocean

Posted on 25 June 2015 by Guest Author

This is a re-post from ClimateSight

Around 55 million years ago, an abrupt global warming event triggered a highly corrosive deep-water current to flow through the North Atlantic Ocean. This process, suggested by new climate model simulations, resolves a long-standing mystery regarding ocean acidification in the deep past.

The rise of CO2 that led to this dramatic acidification occurred during the Paleocene-Eocene Thermal Maximum (PETM), a period when global temperatures rose by around 5°C over several thousand years and one of the largest-ever mass extinctions in the deep ocean occurred.

The PETM, 55 million years ago, is the most recent analogue to present-day climate change that researchers can find. Similarly to the warming we are experiencing today, the PETM warming was a result of increases in atmospheric CO2. The source of this CO2 is unclear, but the most likely explanations include methane released from the seafloor and/or burning peat.

During the PETM, like today, emissions of CO2 were partially absorbed by the ocean. By studying sediment records of the resulting ocean acidification, researchers can estimate the amount of CO2 responsible for warming. However, one of the great mysteries of the PETM has been why ocean acidification was not evenly spread throughout the world’s oceans but was so much worse in the Atlantic than anywhere else.

This pattern has also made it difficult for researchers to assess exactly how much CO2 was added to the atmosphere, causing the 5°C rise in temperatures. This is important for climate researchers as the size of the PETM carbon release goes to the heart of the question of how sensitive global temperatures are to greenhouse gas emissions.

Solving the mystery of these remarkably different patterns of sediment dissolution in different oceans is a vital key to understanding the rapid warming of this period and what it means for our current climate.

A study recently published in Nature Geoscience shows that my co-authors Katrin Meissner, Tim Bralower and I may have cracked this long-standing mystery and revealed the mechanism that led to this uneven ocean acidification.

We now suspect that atmospheric CO2 was not the only contributing factor to the remarkably corrosive Atlantic Ocean during the PETM. Using global climate model simulations that replicated the ocean basins and landmasses of this period, it appears that changes in ocean circulation due to warming played a key role.

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21 comments


2015 SkS Weekly Digest #25

Posted on 24 June 2015 by John Hartz

SkS Highlights

Eight things we learned from the pope's climate change encyclicalby Adam Vaughan attracted the most comments of the articles posted on SkS during the past week. Vaughan 's article originally appeared in The Guardian and can be accessed by clicking hereThe latest global temperature data are breaking records by John Abraham garnered the second highest number of comments. Needless to say, both articles are extremely topical.

Toon of the Week

2015 Toon 25 

Hat tip to I Heart Climate Scientists

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6 comments


The Carbon Brief Interview: Christiana Figueres

Posted on 23 June 2015 by Guest Author

This is a re-post from the Carbon Brief by Leo Hickman

Christiana Figueres has been the executive secretary of the United Nations Framework Convention on Climate Change (UNFCCC) since July 2010 and was reappointed for a second three-year term in July 2013. Before then, she was a member of the Costa Rican negotiating team at the UNFCCC from 1995-2009. In 1995, she founded the non-profit Center for Sustainable Development of the Americas, based in Washington DC.

 

On defining success at the Paris climate conference this coming December: "If financial support for developing countries to be able to follow that path [to bring their population out of poverty but to do so in a low-carbon, high-resilient way] is made evident, then I think we have success."

The political possibility of limiting the global average temperature rise to 1.5C: "I don't know that it is possible to say right now are we going to end up with 1.5, 1.6, 1.7, 1.8, 1.9C? But it's got to be within that range. There is no doubt that it has to be below 2C."

The legal form of the Paris agreement: "I don't think that the whole agreement is actually going to have the same legal nature [as the Kyoto protocol], but rather there will be several components, key components, that will have different legal nature."

Whether the world could tackle climate change without the UNFCCC: "This has to be done in a way that protects the most vulnerable. That would not occur without the UNFCCC."

How the IPCC can best complement the UNFCCC: "There has been a very clear intent to be more and more guided by science. And you see it in all of the negotiations now that there is much more direct dialogue, in fact, even between the delegates and the scientists, which is a very welcome development."

The usefulness of the IPCC's carbon budgets to the UNFCCC: "I think [they have] brought a sense of realism and a sense of urgency into this discussion."

The challenge of reviewing and aggregating the INDCs [intended nationally determined contributions]: "What we have here is a fruit salad. We have apples, we have pears and we, in fact, even have bananas."

The importance of the Sustainable Development Goals (SDGs) and the UNFCCC: "If we do not address climate change in a timely fashion, we will wipe out all the development gains that have been made in the past 15-20 years. We will wipe that out."

The challenge for the UN of managing these parallel, inter-related processes: "When I first saw it I thought how is this going to be possible, and it is very, very difficult, but...we will remember 2015 as being a very important year in the history of the design of mankind."

On reports that the French will present their own text for a climate deal, if progress at the UNFCCC is slow: "They are not going to come with their own text. This is not a Copenhagen 2.0."

 

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6 comments


New study links global warming to Hurricane Sandy and other extreme weather events

Posted on 22 June 2015 by John Abraham

One of the hottest areas of climate research these days is on the potential connections between human emissions, global warming, and extreme weather. Will global warming make extreme weather more common or less common? More severe or less severe?

New research, just published today in Nature Climate Change helps to answer that question by approaching the problem in a novel way. In short yes, human emissions of greenhouse gases have made certain particular weather events more severe. Let’s investigate how they arrived at this conclusion.

Lead author Kevin Trenberth and his team recognized that there are two potential ways a warming climate may lead to weather changes. The first way is through something called thermodynamics. We experience thermodynamics in our own lives. Warm air can be more humid than cold air; we feel that difference throughout the year. Also, warm air evaporates water more quickly. That’s why hair blow dryers and restroom hand dryers usually use heated air. It’s why puddles evaporate more quickly on hot days.

In short, the atmosphere can become either warmer and wetter or warmer and dryer, depending on where you are. The general rule of thumb is that areas which are currently dry will become drier; areas that are currently wet will become wetter; and rains will occur in heavier downbursts.

The scientists list the following questions as a guide to their study.

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7 comments


2015 SkS Weekly News Roundup #25B

Posted on 21 June 2015 by John Hartz

2015 is likely to beat 2014 as the warmest year on record

The Earth just had its warmest May on record, hottest spring and mildest year-to-date, according to new data released Thursday. The climate statistics indicate the year is on course to set another milestone for the warmest year on record, surpassing the previous warmest year, set in 2014.

The data, released by the National Oceanic and Atmospheric Administration (NOAA), also bolsters the clarion call for climate action released by Pope Francis, since they are a sign of longterm warming caused by human activities, scientists said.

According to NOAA, May was not only the warmest such month on record, globally, coming at 1.57 degrees Fahrenheit above the 20th century average, but it also blew away the old record by 0.14 degrees Fahrenheit. The old record was set just last year, indicating that 2015 is running hotter than 2014. (Typically, these records are exceeded by smaller margins of 0.1 or 0.2 degrees Fahrenheit.)

2015 is likely to beat 2014 as the warmest year on record by Andrew Freedman, Mashable, June 18, 2015


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2015 SkS News Bulletin #5: Pope Francis & Climate Change

Posted on 19 June 2015 by John Hartz

Behind the scenes with the Pope's secret science committee

Several dozen of the world’s most prominent scientists sprang from their seats and left the Vatican hall where they were holding a conference on the environment in May 2014. They were bound for a meet-and-greet with Pope Francis at the modest Vatican hotel where he lives, the Domus Sanctae Marthae.

Among the horde was Veerabhadran Ramanathan, a climate scientist at the Scripps Institution of Oceanography. Since 2004, he has also been a member of a 400-year-old collective, one that operates as the pope’s eyes and ears on the natural world: the Pontifical Academy of Sciences.

Behind the Scenes With the Pope's Secret Science Committee by Eric Roston, Bloomberg, June 16, 2015


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Explainer: the models that help us predict climate change

Posted on 19 June 2015 by Guest Author

By Kamal Puri, Australian Bureau of Meteorology; Aurel Moise, Australian Bureau of Meteorology; Robert Colman, Australian Bureau of Meteorology, and Tony Hirst, CSIRO

What will the weather be like next week, next season, or by the end of the century? In the absence of a second Earth to use in an experiment, global weather and climate model simulations are the only tools we have to answer these questions.

Having access to this information is vital for the community, government and industries to make informed decisions – this includes sectors like tourism, natural resource management, agriculture and emergency services to name a few.

Weather and climate may never be completely predictable, but the science has now come far enough for us to be more confident when it comes to knowing whether it will rain this afternoon and for projecting what Australia’s climate may look like many decades in the future.

We’re also getting better at predicting the next season or two, so that we can be more prepared to respond to the extremes in weather like cyclones, heatwaves and flooding rains that already impact Australian communities.

Climate modelling from CSIRO on Vimeo.

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1 comments


Eight things we learned from the pope's climate change encyclical

Posted on 18 June 2015 by Guest Author

Pope Francis has released an unprecedented encyclical on climate change and the environment. The 180-page document calls on rich nations to pay their “grave social debt” to poorer countries and lambasts the UN climate talks for a lack of progress. Here are eight things we learned:

1) He thinks we should phase out coal

While renewable power from wind and solar gets up to speed as a solution to our energy needs, it’s worth considering gas over coal, he said:

We know that technology based on the use of highly polluting fossil fuels – especially coal, but also oil and, to a lesser degree, gas – needs to be progressively replaced without delay. Until greater progress is made in developing widely accessible sources of renewable energy, it is legitimate to choose the lesser of two evils or to find short-term solutions.

He says more than 20 years of summits have produced “regrettably few” advances on efforts to cut carbon emissions and rein in global warming. The encyclical says:

It is remarkable how weak international political responses have been. The failure of global summits on the environment make it plain that our politics are subject to technology and finance. There are too many special interests, and economic interests easily end up trumping the common good and manipulating information so that their own plans will not be affected.

3) He doesn’t like carbon trading

In this passage he seems to be referring to the only current global carbon trading scheme, the CDM:

The strategy of buying and selling “carbon credits” can lead to a new form of speculation which would not help reduce the emission of polluting gases worldwide. This system seems to provide a quick and easy solution under the guise of a certain commitment to the environment, but in no way does it allow for the radical change which present circumstances require. Rather, it may simply become a ploy which permits maintaining the excessive consumption of some countries and sectors.

4) But he does like community energy

From Francis’s point of view, small and local is beautiful:

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83 comments


2015 SkS Weekly News Roundup #25A

Posted on 17 June 2015 by John Hartz

Americans are again getting more worried about the climate

The financial crisis made Americans less worried about climate change. The Democrats’ attempt to pass sweeping climate legislation in 2009 and 2010 probably reduced Americans’ anxiety level as well, as paradoxical as that may sound. But now Americans are getting more worried again.

About 69 percent of adults say that global warming is either a “very serious” or “somewhat serious” problem, according to a new Pew Research Center poll, up from 63 percent in 2010. The level of concern has still not returned to that of a decade ago; in 2006, 79 percent of adults called global warming serious.

It’s impossible to know exactly why concern about the climate fell — and why skepticism that global warming was real increased — starting around 2008. Both economics and politics probably play a role. The financial crisis and recession made Americans more worried about the immediate condition of the economy, rather than about the long-term condition of the planet.

Americans Are Again Getting More Worried About the Climate by David Leonhardt, New York Times, June 16, 2015


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