Arguments
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?
New study shows warm waters are melting Antarctica from below
Posted on 13 November 2014 by John Abraham
Just this week, a new study has appeared which describes a clever method for measuring the flows of ocean currents and their impacts on ice shelves. This study has identified a major mechanism for melting ice in the Southern Hemisphere.
The paper, co-authored by Andrew Thompson, Karen Heywood, and colleagues is very novel. The scientists used sea gliders to identify water flows that bring warm waters to the base of ice shelves in Antarctica. As I’ve written before, ocean currents are complex; you cannot neglect their impact on the Earth’s climate.
In some parts of the ocean, dense waters near the surface fall to the ocean floor and spread across the globe. In other regions, waters from the deep rise to the surface. Similarly, waters move horizontally and carry their heat with them. In some cases the surface waters and the mid-depth waters flow in different directions.
But regardless of the direction of flow, these waters carry energy with them. This process, often called “advection,” results in a major redistribution of heat across the globe. Sometimes, warm waters flow into cold regions, transferring heat, and melting ice. It is this phenomenon that was at the center of the current paper.
Fluids sometimes move as large directional masses (sometimes called bulk motion) caused by some agent of motion, for instance winds that blow over the surface and drag waters. Other motions are characterized by swirls and eddies – not unidirectional flow. This type of motions is called eddy-induced transport. A determination of which type of transport dominates and where they dominate is important to understanding Antarctic ice melt.
2014 SkS Weekly News Roundup #46A
Posted on 12 November 2014 by John Hartz
- Ahead of global talks, all eyes on U.S. contribution to Climate Fund
- A tricky transition from fossil fuel
- Capping warming at 2 C not enough to avert disaster
- Conservatives don't hate climate change, they hate the proposed solutions
- G20 states spend $88bn in fossil fuel exploration subsidies
- Global warming worsening watery dead zones
- Interview with Bill McKibben: 'When the history of this time is written'
- New U.S.-China climate deal is a game changer
- Post climate pact, IEA warns fossil fuel trends dire
- Republicans vow to fight E.P.A. and approve Keystone pipeline
- The end of beaches? Why the world’s shorelines are in serious trouble
- Underwater 'storms' may hold key to melting Antarctic ice
- U.S. and China announce new climate goals
- Use the Web? Congrats, you’re an environmentalist.
- What you need to know about U.S.-China Climate Pact
A tricky transition from fossil fuel
Denmark, a tiny country on the northern fringe of Europe, is pursuing the world’s most ambitious policy against climate change. It aims to end the burning of fossil fuels in any form by 2050 — not just in electricity production, as some other countries hope to do, but in transportation as well.
Now a question is coming into focus: Can Denmark keep the lights on as it chases that lofty goal?
Lest anyone consider such a sweeping transition to be impossible in principle, the Danes beg to differ. They essentially invented the modern wind-power industry, and have pursued it more avidly than any country. They are above 40 percent renewable power on their electric grid, aiming toward 50 percent by 2020. The political consensus here to keep pushing is all but unanimous.
A Tricky Transition From Fossil Fuel: Denmark Aims for 100 Percent Renewable Energy by Justin Gillis, New York Times, Nov 10, 2014
Remote-control robots reveal why the Antarctic ice sheet is melting
Posted on 12 November 2014 by Guest Author
This article was originally posted on The Carbon Brief on Nov 10, 2014
by Robert McSweeney
At current rates, ice sheet loss will become the most significant contributor to global sea level rise during this century, yet there is still a lot that scientists don't know about the underlying causes. This is partly because Antarctica is such a difficult place to take measurements.
But now robotic underwater gliders are giving scientists new insight into why the Antarctic ice sheet is melting.
Ice sheets
An ice sheet is a huge layer of ice that sits on land. The two on the Earth today are found on Antarctica and Greenland, but in the last ice age there were also ice sheets on North America and northern Europe.
The Antarctic ice sheet spans more than 14 million square kilometers, which is roughly the same size as the US and Mexico put together. The ice sheet also spills out onto the surrounding ocean in the form of ice shelves.
The Intergovernmental Panel on Climate Change (IPCC) estimates that the Antarctic ice sheet is currently losing around 150 billion tonnes of ice per year. One of the main areas of ice loss is from the Antarctic Peninsula, shown in the red rectangle in the map below.
Map of Antarctica. Antarctic Peninsula shown in red rectangle. Creative Commons.
More research confirming large methane leakage from shale boom
Posted on 11 November 2014 by gws
More research published in 2014 is consistent with the previous notion that the shale boom in the US has been, and likely still is, causing much larger fugitive methane (and higher hydrocarbon) emissions than claimed by the industry.
In a recent publication in Earth's Future, a new journal published by the American Geophysical Union (AGU) dedicated to "global change and sustainability", a German-US team of researchers showed increasing atmospheric methane abundances over two rapidly developing shale areas, the Bakken and Eagle Ford shales in North Dakota and south Texas, respectively. Their methane emissions estimate is based on the difference in atmospheric methane in these areas between the years prior said rapid development, 2006-2008, and during it, 2009-2011.
Mapping methane anomalies
Data for the authors' analyses came from the European Space Agency (ESA) ENVISAT's instrument SCIAMACHY, and is unfortunately not available beyond early 2012, when contact with the satellite was lost. The instrument measured the total amount of methane in the atmosphere, the overwhelming amount of which is in the lower 10-12 km, the troposphere. Based on the resolution of the instrument, and the amount of time the satellite spent overhead, the authors used 3 years of data to get high enough precision for their study. They also accounted for how winds displaced the emitted methane differently between the two study periods. The result is depicted in Figure 1 below.
Figure 1: Shown are two latitude-longitude maps of the difference in atmospheric methane abundance (expressed as a mole fraction), or methane anomaly, for the period 2009–2011 relative to the period 2006–2008. The locations of oil and gas wells are shown in pink. The regions used to estimate shale area emissions are red-rimmed. The corresponding regions used to determine the background values are framed by the green dashed lines. Averaged near-surface wind differences between the periods are illustrated by dark grey arrows.
We must manage global warming risks by cutting carbon pollution, top scientists conclude
Posted on 10 November 2014 by dana1981
Last week, the Intergovernmental Panel on Climate Change (IPCC) published its latest Synthesis Report, summarizing the scientific research on the causes and impacts of global warming, and how we can mitigate its consequences. The report included various graphs showing how we’re changing the Earth’s climate, and concluded that humans are causing rapid and dangerous global warming.
Human influence on the climate system is clear, and recent anthropogenic emissions of greenhouse gases are the highest in history. Recent climate changes have had widespread impacts on human and natural systems.
Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, and sea level has risen.
Much of the report focused on the risks associated with these rapid climate changes. Fundamentally, climate change is a risk management problem. Even if you’re sceptical of the vast body of scientific research pointing to dangerous and potentially catastrophic climate change, there’s a very good chance the experts and their supporting evidence are correct and your scepticism is misplaced. The IPCC report put those risks into perspective,
Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems. Limiting climate change would require substantial and sustained reductions in greenhouse gas emissions which, together with adaptation, can limit climate change risks.
Many aspects of climate change and associated impacts will continue for centuries, even if anthropogenic emissions of greenhouse gases are stopped. The risks of abrupt or irreversible changes increase as the magnitude of the warming increases.
The key word here is “irreversible,” and it’s used 14 times in the IPCC’s latest Summary for Policymakers. For example, if ice sheets in Greenland and Antarctica collapse into the ocean, as they’ve already begun to, we can’t take the ice out of the ocean and put it back on land. That lost ice and the sea level rise it causes are irreversible impacts.
Conversely, policies to slow global warming are reversible. A new study by scientists at Duke University found that the widespread rejection of climate science by American political conservatives is in large part due to their distaste for the proposed solutions. Climate contrarians are afraid that climate policies will slow economic growth, despite evidence to the contrary.
However, if it turns out that the sceptics are right in their optimism that the best case climate scenario will occur, and if we go too far in our efforts to reduce carbon pollution, we can easily scale those efforts back. We can’t reanimate extinct species, but we can adjust climate policies as needed.
Speaking of species extinctions, the IPCC discussed that serious threat as well,
A large fraction of species face increased extinction risk due to climate change during and beyond the 21st century, especially as climate change interacts with other stressors (high confidence). Most plant species cannot naturally shift their geographical ranges sufficiently fast to keep up with current and high projected rates of climate change in most landscapes; most small mammals and freshwater molluscs will not be able to keep up at the rates projected under RCP4.5 and above in flat landscapes in this century (high confidence).
Marine species are also at risk due to the dual threats of warming oceans and ocean acidification, both of which are caused by carbon pollution from burning fossil fuels.
Since the beginning of the industrial era, oceanic uptake of CO2 has resulted in acidification of the ocean; the pH of ocean surface water has decreased by 0.1 (high confidence), corresponding to a 26% increase in acidity
The IPCC concluded that if we take serious action to reduce fossil fuel consumption and greenhouse gas emissions, we can limit the future increase in ocean acidity to about 16%. If we continue on a business-as-usual fossil fuel dependent path, ocean acidity will increase by around 100%, with dire consequences for marine ecosystems. This will also hurt our fisheries and contribute to food insecurity.
Climate change is projected to undermine food security (Figure SPM.9). Due to projected climate change by the mid-21st century and beyond, global marine species redistribution and marine biodiversity reduction in sensitive regions will challenge the sustained provision of fisheries productivity and other ecosystem services (high confidence) ... Global temperature increases of ~4°C or more14 above late-20th century levels, combined with increasing food demand, would pose large risks to food security globally (high confidence).
As these figure below from the report also illustrates, about 70% of studies indicate that crop yields will decline as the Earth continues to warm after 2030, with a high chance that yields could decline by 25% or more by the end of the century if we continue on our current path.
Summary of projected changes in crop yields, due to climate change over the 21st century. Yellow indicates studies that project crop yield decreases, blue indicates studies projecting increases. Illustration: IPCC AR5
2014 SkS Weekly Digest #45
Posted on 9 November 2014 by John Hartz
SkS Highlights
The 2014 SkS Weekly News Roundup #45B attracted the highest number of comments of the items posted on SkS during the past week. Dana's article, Weather Channel co-founder John Coleman prefers conspiracies to climate science garnered the second highest number.
Toon of the Week
See: Voters put climate change policy in the hands of climate change denier by David Horsey, Los Angeles Times, Nov 7, 2014
2014 SkS Weekly News Roundup #45C
Posted on 8 November 2014 by John Hartz
- Biggest Brazil metro area desperate for water
- Climate change is messing with pollination
- Climate economics expert urges "critical" investment shift
- Climate talks grapple with regional carbon markets
- Environmentalists mostly counting election losses
- Higher temperatures may result in fewer bees
- Mitch McConnell feels a “deep responsibility” to block climate action
- Poland rejects IPCC target of zero emissions by 2100
- Surprise! This GOP Senator's theory about volcanoes and climate change is totally wrong.
- This man is about to become one of America’s most powerful climate villains
- Waiting for El Niño. Still. Again.
- World losing battle against global warming
Biggest Brazil metro area desperate for water
It’s been nearly a month since Diomar Pereira has had running water at his home in Itu, a commuter city outside Sao Paulo that is at the epicenter of the worst drought to hit southeastern Brazil in more than eight decades.
Like others in this city whose indigenous name means “big waterfall,” Pereira must scramble to find water for drinking, bathing and cooking. On a recent day when temperatures hit 90 degrees (32 Celsius), he drove to a community kiosk where people with empty soda bottles and jugs lined up to use a water spigot. Pereira filled several 13-gallon containers, which he loaded into his Volkswagen bug.
“I have a job and five children to raise and am always in a rush to find water so we can bathe,” said Pereira, a truck driver who makes the trip to get water every couple of days. “It’s very little water for a lot of people.”
Biggest Brazil metro area desperate for water, AP/Washington Post, Nov 7, 2014
New study questions the accuracy of satellite atmospheric temperature estimates
Posted on 7 November 2014 by John Abraham
Over the past decades, scientists have made many measurements across the globe to characterize how fast the Earth is warming. It may seem trivial, but taking the Earth’s temperature is not very straightforward. You could use temperature thermometers at weather stations that are spread across the globe. Measurements can be taken daily and information sent to central repositories where some average is determined.
A downside of thermometers is that they do not cover the entire planet – large polar regions, oceans, and areas in the developing world have no or very few measurements. Another problem is that they may change over time. Perhaps the thermometers are replaced or moved, or perhaps the landscape around the thermometers changes which could impact the reading. And of course, measurements of the ocean regions are a whole other story.
An alternative technique is to use satellites to extract temperatures from radiative emission at microwave frequencies from oxygen in the atmosphere. Satellites can cover the entire globe and thereby avoid the problem with discrete sensors. However, satellites also change over time, their orbit can change, or their detection devices can also change.
Another issue with satellites is that the measurements are made throughout the atmosphere that can contain contaminants to corrupt the measurement. For instance, it is possible that water droplets (either in clouds or precipitation) can influence the temperature readings.
So, it is clear that there are strengths and weaknesses to any temperature measurement method. You would hope that either method would tell a similar story, and they do to some extent, but there are key differences. Basically, the lower atmosphere (troposphere) is heating slower than the Earth surface.
In fact, for the time period 1987–2006, the temperatures among the four groups that collect satellite data ranges from 0.086°C per decade to 0.22°C per decade. In more recent years, the trend is much reduced, and for two of the leading satellite groups (University of Alabama at Huntsville and Remote Sensing Systems), temperatures are basically flat.
2014 SkS Weekly News Roundup #45B
Posted on 6 November 2014 by John Hartz
- Britain had one of warmest and wettest years on record
- Global warming could make your pollen allergies a lot worse
- How does the IPCC know climate change is happening?
- Meet the Senate's new Climate Denial Caucus
- Midterm elections, the Senate, and Republican science denial
- Millions of Asians exposed to big climate disasters - Oxfam
- No quick fix for overpopulation — let’s focus on climate
- Our kids need to learn about climate change
- ‘Remarkable opportunity' for global economy in upcoming climate talks
- Science in a Republican Senate: The Good, the Bad and the Ugly
- Seven myths about disasters
- The worst climate pollution is carbon dioxide
- There should be no more international reports on climate science
- UN to investigate claims that UK spies infiltrated climate talks
- Why two crucial pages were left out of the latest U.N. climate report
Britain had one of warmest and wettest years on record
The UK is on course to experience the warmest and one of the wettest years since records began more than a century ago, feeding fears that future droughts and flash floods could cost lives.
Figures from the Met Office show January to October has been the warmest since records began in 1910, and also the second-wettest. Unless November and December are extremely cold, 2014 will be the hottest year on record.
Experts say this the result of climate change, which they warn could place a burden on the NHS as Britons struggling to cope with future heatwaves end up in hospital.
Britain had one of warmest and wettest years on record by Press Association/The Guardian, Nov 4, 2014
Looking after the right forests benefits the climate
Posted on 6 November 2014 by MarkR
Dr Nadine Unger and other forest-science experts (here and at RealClimate) have recently written about whether saving forests will reduce future climate change. Dr Unger mentions a recent "landmark deal" on sustainable forestry and suggests it's a "bad bet", the others disagree.
I'm convinced that it's a very good bet. If we want to limit global warming, then we have a carbon budget that we can spend, and we can spend this budget by chopping down trees or by doing other things like burning oil and gas. The "landmark deal" aims to keep carbon locked up in forests, clearing space in the budget. Dr Unger argues that planting trees doesn't always help the climate, but her technical points are not really relevant to the tropical forests covered in this particular "landmark deal".
Trees and Temperatures
One way in which trees affect temperatures is that they tend to be darker than grasses or snow. Just like how a black car feels hot to the touch on a bright, sunny day, trees absorb extra heat and warm up.
This is balanced by how they absorb carbon. Clearing forests releases this carbon (mostly) as carbon dioxide (CO2), a warming greenhouse gas. There are other processes too, and researchers have calculated the total effect that forests have on temperatures. Dr Unger mentions the surprising result that planting trees in colder areas can boost warming (e.g. Bonan et al., 2008).
However, tropical forests are very dense. Powered by bright sunlight year round and fuelled by heavy rainfall, they suck up enormous amounts of carbon. There's wide agreement that they have an overall cooling effect, and one of Dr Unger's own references (Jackson et al., 2008) states straight up that "Tropical projects—avoided deforestation, forest restoration, and afforestation—provide the greatest climate value".
In general, one of Dr Unger's points is that in many developed countries, like the US and UK, planting trees isn't going to help reduce global warming. This is probably true, but not relevant for the "landmark deal" under discussion. This is about Reducing Emissions from Deforestation and Forest Degradation (REDD+) in Developing Countries (more details are in a note that I researched and wrote for the UK Parliament).
Here's a map of countries doing REDD+ projects. It's dominated by tropical forests in countries like Brazil, Peru and Indonesia.
Figure 1 Map of countries with current REDD+ projects, darker shade means that the country has more projects. Modified from this map, produced by CIFOR.
2014 SkS Weekly News Roundup #45A
Posted on 4 November 2014 by John Hartz
- 29 bullets tell all about climate challenge
- Abbott must put climate change at front of the G20 agenda in Brisbane
- Amazon rainforest losing ability to regulate climate, scientist warns
- Climate change fight affordable, cut emissions to zero by 2100
- Climate depression is for real. Just ask a scientist
- Denmark considers phasing out coal by 2025 in big green shift
- G20: Australia makes token concession on climate change
- IPCC report: six graphs that show how we're changing the world's climate
- New IPCC report: busting myths, both scientific and economic
- Panel’s latest report misses global slumber party on energy research
- Stark IPCC climate report shows the time for talking is over
- The 10 things you need to know from the new IPCC climate report
- The implications of the US midterm elections for climate change policy
- U.N. panel warns of dire effects from lack of action over global warming
- When thawing glaciers release pollutants
29 bullets tell all about climate challenge
The results are in. Yesterday the United Nations Intergovernmental Panel on Climate Change released it final report crystallizing 13 months of work by more than 800 scientists. The “synthesis report” gives a no-nonsense assessment of how the climate is changing, what is causing the change, the impacts the changes will have on us and the planet, and the “mitigation” steps we should take to prevent the impacts from getting worse. The recommendations are intended first and foremost for national leaders, who in 2015 will make what may be a last-chance effort to reach a binding global climate treaty.
Although the report’s authors try to give a condensed snapshot of the most important data and recommendations, the document still clocks in at 116 pages. I will attempt, here, to capture what you need to know most, in 29 bullets. Forgive the staccato.
29 bullets tell all about climate challenge by Mrak Frischetti, Scientific American, Nov 3, 2014
Concluding instalment of the Fifth IPCC Assessment Report:
Posted on 4 November 2014 by John Hartz
This article is a reprint of a press release posted by the Intergovernmental Panel on Climate Change on Nov 2, 2014
Climate change threatens irreversible and dangerous impacts, but options exist to limit its effects
COPENHAGEN, Nov 2 – Human influence on the climate system is clear and growing, with impacts observed on all continents. If left unchecked, climate change will increase the likelihood of severe, pervasive and irreversible impacts for people and ecosystems. However, options are available to adapt to climate change and implementing stringent mitigations activities can ensure that the impacts of climate change remain within a manageable range, creating a brighter and more sustainable future.
These are among the key findings of the Synthesis Report (long version)/Synthesis Report (approved summary for policymakers) released by the Intergovernmental Panel on Climate Change (IPCC) on Sunday. The Synthesis Report distils and integrates the findings of the IPCC Fifth Assessment Report produced by over 800 scientists and released over the past 13 months – the most comprehensive assessment of climate change ever undertaken.
“We have the means to limit climate change,” said R. K. Pachauri, Chair of the IPCC. “The solutions are many and allow for continued economic and human development. All we need is the will to change, which we trust will be motivated by knowledge and an understanding of the science of climate change.”
The Synthesis Report confirms that climate change is being registered around the world and warming of the climate system is unequivocal. Since the 1950s many of the observed changes are unprecedented over decades to millennia. “Our assessment finds that the atmosphere and oceans have warmed, the amount of snow and ice has diminished, sea level has risen and the concentration of carbon dioxide has increased to a level unprecedented in at least the last 800,000 years,” said Thomas Stocker, Co-Chair of IPCC Working Group I.
The report expresses with greater certainty than in previous assessments the fact that emissions of greenhouse gases and other anthropogenic drivers have been the dominant cause of observed warming since the mid-20th century.
The impacts of climate change have already been felt in recent decades on all continents and across the oceans.
Weather Channel co-founder John Coleman prefers conspiracies to climate science
Posted on 4 November 2014 by dana1981
The Weather Channel co-founder John Coleman was recently interviewed by Megyn Kelly on Fox News, calling human-caused global warming “a myth.” The interview was then amplified through the media echo chamber, including an article at left-leaning Huffington Post, and Coleman was subsequently interviewed on CNN’s Reliable Sources.
Coleman has publicly denied the scientific reality of human-caused global warming for years, telling Fox News in 2008 that he wanted to sue Al Gore, for example. There’s no new content in these latest interviews; just the usual long-debunked climate myths and conspiracy theories. Coleman is apparently considered a credible climate interviewee because he was instrumental in creating The Weather Channel 32 years ago, but he’s woefully misinformed when it comes to climate science.
Coleman Denies Basic Climate Science
In his Fox News interview, Coleman said,
The Antarctic ice cap is at an all-time record high in both coverage and thickness, and the Arctic ice cap at the North Pole is at the highest it has been in several years. It’s in its so-called normal range since we got satellite observations that can measure it. So not only is the ice not melting, more polar bears are alive and happy today than in 100 years.
Each of these points is either wrong or misleading.
Although more Arctic sea ice survived this year than in the record-shattering melt of 2012, in 2014 the ice was nevertheless at its 6th-lowest level in thousands of years. About 70% of the sea ice in the Arctic has disappeared over the past three decades, mainly due to human-caused global warming. This rapid decline is well outside “the normal range” of Arctic sea ice extent and volume.
Reconstructed Arctic sea ice extent over the past 1,450 years, from Kinnard et al. (2011).
2014 SkS Weekly Digest #44
Posted on 3 November 2014 by John Hartz
SkS Highlights
Dana's Republican politicians aren't climate scientists or responsible leaders is another in a long-line of insightful critiques of how prominent U.S. politicians are addressing the science and ramifications of man-made climate change. As to be expected, Dana's article generated the highest number of comments of the articles posted on SkS during the past week.
Toon of the Week
h/t to I Heart Climate Scientists
Why the IPCC synthesis report is necessary but not sufficient to secure a response to climate change
Posted on 1 November 2014 by Guest Author
This article was originally posted on The Carbon Brief on Oct 31, 2014
by Simon Evans
On Sunday 2nd November, the Intergovernmental Panel on Climate Change (IPCC) will publish its latest synthesis report, distilling the latest knowledge on what UN chief Ban Ki-Moon has called the greatest threat ever faced by humanity.
The synthesis report will wrap up the IPCC's fifth assessment (AR5) of climate change. It draws together information from the IPCC's reports on the science of climate change, climate impactsand the ways climate risks can be addressed.
It takes a mammoth collective effort on the part of scientists, economists and policymakers to produce these IPCC reports. Is it worth it?
We've collected a range of views on the need for, and wider significance of, the IPCC's work. These suggest it remains a necessary but not sufficient part of the job of addressing climate change.
The synthesis report is necessary
Does the world need an IPCC, asks former IPCC chair and former scientific adviser to the UK government Bob Watson. "My answer would be absolutely yes," he says. "I think it's critically important the IPCC does routinely report back on what we know."
The synthesis report collects together scientific opinion on the technical and socio-economic aspects of the causes of climate change, the risks it poses and the options for adaptation and mitigation. It is unique in taking such a wide ranging and considered view of climate.
There's a huge amount of information to distill. The idea of the synthesis report is to take all that knowledge and to mould it into a coherent and accessible narrative.
The report is then checked, tweaked and approved line by line by government representatives, working with the scientists that wrote it. This gives the synthesis report added credibility, at least in theory, because all governments have signed off on what it says.
Denmark's minister of climate and energy Rasmus Helveg-Petersen told RTCC this process "eliminates the option of people inventing their own numbers… First we have to agree on the facts, then we can decide the course of action."
Government sign-off also means that the tone of the synthesis report is a reflection of how seriously governments take the risks of climate change. The language of the synthesis report is particularly significant when you consider that it is more widely read by policymakers than any of the IPCC's other reports.
The synthesis report is useful
So what do policy makers do with the synthesis report once they've chewed over its findings? There seem to be two primary uses: guiding policy choices and arguing for their adoption.
2014 SkS Weekly News Roundup #44B
Posted on 31 October 2014 by John Hartz
- 5 ideas for protecting New York from the next Sandy
- Climate scientists aren’t too alarmist. They’re too conservative
- Direct Action is like a dodgy laundry powder that never gets the climate clean
- Emissions trading will be back in the game if Direct Action proves ineffective
- Fossil fuels won’t benefit Africa in absence of sound environmental policies
- Hot enough? Things are going to get hotter
- How Interstellar made Michael Caine think again about climate change
- If we want to make climate action happen we need to hear about the solutions
- New study shows three abrupt pulse of carbon dioxide during last deglaciation
- Poor countries tap renewables at twice the pace of rich
- Research reveals current climate engagement strategies are failing to reach young people
- Rising temperatures: A month versus a decade
- U.N. talks of tough global climate targets, vague on national action
- UN warns of irreversible climate change
- Why Republicans keep telling everyone they’re not scientists
5 ideas for protecting New York from the next Sandy
It’s been two years since Superstorm Sandy, and much of New York City is still vulnerable to flooding from storm surges. And as global sea levels continue to rise, that flooding risk will only increase. While Sandy caused around $19 billion in damages and economic losses in New York City, the same storm would cost the city $90 billion in 2050, according to a recent analysis by the city government. According to city risk assessments, 400,000 people already live in an area that has a 1 percent chance of flooding in any given year.
There are a number of proposed solutions for this ever-worsening problem, ranging from the practical to the whimsical. The Huffington Post took a look at some of the proposed solutions (including some conceived even before Sandy brought attention to the issue), as well as the official recommendations of the New York City Special Initiative for Rebuilding and Resiliency, a Bloomberg administration effort to build a more resilient city post-Sandy. While some of these ideas may seem far-fetched, these are all real proposals.
5 Ideas for Protecting New York From The Next Sandy (Some Of Which Are A Little Nuts) by Katherine Boehrer, The Huffington Post, Oct 29, 2014
New research quantifies what's causing sea level to rise
Posted on 30 October 2014 by John Abraham
There have been a number of studies that have come out recently on ocean warming and sea-level rise. Collectively, they are helping scientists coalesce around an emerging understanding of climate change and its impact on the Earth. Most recently, a study by scientists Sarah Purkey, Gregory Johnson, and Don Chambers was published. This team was responsible for a 2010 paper that was groundbreaking in that it quantified very deep (abyssal) sea warming. This latest paper is, in some respects, a continuation of that work.
The researchers recognized that changes to the sea levels are mainly caused by thermal expansion of ocean waters as they heat, changes to the saltiness of water, and by an increase in ocean waters as ice melts and flows into the sea. The total annual sea level rise is about 3 mm per year – the question is, how much of that is from expansion and how much is from melting?
Greg Johnson
The researchers used a few tools to answer this question. One tool was ocean bottom pressure measurements. If you can measure changes to ocean pressure, you can deduce how much water is in the ocean. Another tool is through an inventory approach. This inventory method quantifies how much glaciers retreat, polar ice melts, and changes to water storage on land. The paper reports that both methods agree with each other. They conclude that increased water in the oceans is causing about 1.5–1.8 mm per year of sea level rise. The actual value depends, in part, on which years are under consideration.
The authors don’t just consider the ocean as a whole. They break the ocean regions into seven different sections. The reason for this subdivision is that the change to ocean levels is not uniform. In some reasons, waters are rising quickly, in other regions, the rise is much slower or zero. One region for regional variability is that the Earth’s gravity is changing.
For instance, there is so much ice in Greenland and Antarctica that is melting and flowing into the ocean, the mass of these two regions is being reduced; therefore, the pull of gravity toward Greenland and Antarctica is changing. As a result, we expect water levels near Greenland and Antarctica may actually fall as those ice sheets melt.
2014 SkS Weekly News Roundup #44A
Posted on 29 October 2014 by John Hartz
- A chronicler of warnings denied
- Arctic Ice Melt Seen Doubling Risk of Harsh Winter in EU
- Building for the next big storm
- Carbon trading edges closer as UN brokers deal
- Five things to know about 2014 global temperatures
- Great Barrier Reef protection plan 'ignores the threat of climate change'
- Maybe you can change people’s minds about climate change after all
- New study strengthens link between Arctic sea-ice loss and extreme winters
- Our planet's primal scream — Is anyone listening?
- Q&A: The EU's 2030 climate targets
- Revealed: What the Southern Ocean's ice belt means for sea level rise
- The Coalition’s 19th-century colonial time warp on climate
- Two years after Sandy, there's still work to be done
- UN climate change draft sees risks of irreversible damage
- With storms intensifying, Milwaukee braces for bigger floods
A chronicler of warnings denied
Naomi Oreskes is a historian of science at Harvard, but she is attracting wide notice these days for a work of science fiction.
“The Collapse of Western Civilization: A View From the Future,” written with Erik M. Conway, takes the point of view of a historian in 2393 explaining how “the Great Collapse of 2093” occurred.
“Without spoiling the story,” she told me, “I can tell you that a lot of what happens — floods, droughts, mass migrations, the end of humanity in Africa and Australia — is the result of inaction to very clear warnings” about climate change caused by humans. The 104-page book was listed last week as the No. 1 environmental best-seller on Amazon. Dr. Oreskes, 55, spoke with me for two hours at her home in Concord, Mass., and later again by telephone. Here is an edited and condensed version of the conversations.
A chronicler of warnings denied by
Republican politicians aren't climate scientists or responsible leaders
Posted on 28 October 2014 by dana1981
Republican Senate Minority Leader Mitch McConnell is hoping to become the Senate Majority Leader after the forthcoming election on November 4th, although despite hailing from conservative Kentucky, McConnell is in a very tight race. The Cincinnati Enquirer editorial board recently had a long discussion with McConnell and tried to pin him down on the subject of global warming.
McConnell wouldn’t directly answer whether he believes in climate change.
Enquirer’s editorial board volleyed several questions about what it would take to convince him of climate change. He turned the subject every time to jobs. McConnell said he believes imposing regulations to reduce greenhouse gases blamed for climate change would only hurt America and not mitigate what other countries, such as China, are doing...
“We can debate this forever,” McConnell said. “George Will had a column in the last year or so pointing out that in the 70s, we were concerned the ice age was coming. I’m not a scientist. I’m interested in protecting Kentucky’s economy.”
Leaving aside McConnell’s reference to the 1970s ice age myth, the cop-out about not being a scientist is a strange and dangerous one.
The role of the ocean in tempering global surface warming
Posted on 27 October 2014 by Guest Author
This is a re-post of an article by Richard Allan for NOAA
It is well known that the surface has warmed over the past few decades, primarily in response to rising concentrations of greenhouse gases. ENSO variability and other natural factors, have additionally contributed toward year-to-year fluctuations about this warming trend (dark red line in Figure 1). Strong El Niño events add a few tenths of a degree Celsius to the global average surface temperatures. However, there has recently been an observed slowing in the rate of surface warming (compare the red and orange trend lines in Figure 1) which may be related in part to a greater number of cold La Niña events in the 2000s compared to previous decades (see article by Climate.gov).
Figure 1: Observed changes in global annual average surface temperature relative to 1961-1990 from the HadCRUTv4 dataset which is updated to account for gaps in data coverage (version 2.0 Long Reconstruction). The temperature difference is compared with 1961-1990 average using data from Cowtan & Way (2014). The rate of warming from 1970-2013 (red trend line) is larger than the rate of warming between 1998-2013 (orange line).
