Lethal Heating: 05/23/16

23/05/2016

10 Things You Should Know About Sea Level Rise And How Bad It Could Be

Washington Post - Rob Motta* | James White* | R. Steven Nerem*

This undated photo courtesy of NASA shows Thwaites Glacier in Western Antarctica. (AFP/Getty Images)

Sea level rise is potentially one of the most damaging results of climate change, but few people understand its risks. Its impacts — financial and otherwise — will spread far from the coasts.
Here are 10 things you should know about sea level rise, what causes it and how bad it might get.

1. There is enough water stored as ice to raise sea level 230 feet.
Most of this ice is located in Antarctica and Greenland. Antarctica, with an area 40 percent greater than the United States, is covered by an ice sheet almost a mile thick that holds about 200 feet equivalent of sea level. Most of that ice is — for now — stable, but scientists are concerned that the massive West Antarctic Ice Sheet, which holds about 11 feet of potential sea level rise, has reached a tipping point and will collapse. Another 23 feet of equivalent sea level is stored as ice in Greenland, and it is melting at an increasing rate. The rest is in glaciers and ice caps spread around the world, and they, too, are generally melting.

2. Sea levels have changed by hundreds of feet in the past.
We generally think of sea level as stable, but sea level has varied a lot over time as we have gone from ice age to ice age at about 100,000-year intervals. At the height of the last ice age, when much of North America was covered in ice, sea level was about 400 feet lower. We are now in a warm period between ice ages; sea level should be peaking and then eventually starting to go down again. But human-caused climate change is altering this cycle.

3. We are changing sea level at a very rapid rate.
While sea level has varied greatly in the past, it has generally changed slowly, over many thousands of years — except when ice sheets collapse. We will explain more on ice sheet collapse later, but prior to about 1900, we know sea level was stable for several thousand years. A warming world is now pushing sea levels higher, and the rate of rise is accelerating.

Environmental Protection Agency, data via National Oceanic and Atmospheric Administration and the Commonwealth Scientific and Industrial Research Organization.

Sea level rose about seven inches during the 20th century. That may not seem like much, but the rate of sea level rise has almost doubled in recent years, and scientists expect that rate to continue to go up. About a third of the current rate of sea level rise is from thermal expansion of the oceans (the water expands like mercury in a thermometer), because they are absorbing about 90 percent of the increased heat from climate change. But in the future, melting ice will play a greater role. Predictions for the year 2100 are in the range of two to three feet, excluding any potential contributions from ice sheet collapse.

4. We could melt it all.
The Earth has already warmed by 1 degree Celsius (1.8 degrees Fahrenheit) above pre-industrial levels. Scientists estimate that if it warms by about 4 to 5 degrees Celsius (7.2 to 9 degrees Fahrenheit), which is projected to happen by the end of the century if we don’t act on climate change, then all the ice will eventually melt. That’s 230 feet of sea level rise.
What the shoreline would look like if all the ice melted, courtesy an excellent interactive map from National Geographic:

If all the ice on Earth melted, this is how North America would change. National Geographic

The curve, or rate at which ice melts, is not directly proportional to time and temperature. In other words, at one-fifth of the temperature rise needed to melt all the ice (about where we are today), it is not likely that exactly one-fifth of all the ice will melt, leading eventually to 46 feet of sea level rise — could be more, could be less. The same is true with melting over time.
Ice sheets and glaciers are currently melting slowly, but there have been times in the past when they have collapsed rapidly, causing sea level to rise by a foot or more per decade — for decades at a time. We may be facing one of those periods in the near future.
Scientists are working to understand how unstable the ice sheets are, and how much additional sea level rise we could see over the current projections, particularly for the short-term (like in the time frame your kids will see). But with 230 feet of potential sea level rise on the table, it doesn’t take a whole lot more melting for a coastal city to be okay in one set of assumptions, and under water in another.

According to a new study, high levels of greenhouse gas emissions could cause oceans to rise by close to two meters in total (over six feet) by the end of the century, and more than 13 meters (42 feet) from Antarctica alone by 2500. (Nature, Rob DeConto, David Pollard)

6. The last time sea levels changed significantly, there weren’t a lot of people around.
When the last ice age ended around 10,000 years ago and sea level started to rise to its present level, there were only about 5 million people on Earth, and they didn’t live in expensive cities right on the coast. Today, in the United States alone, nearly 5 million people live within 4 feet of high tide. So, not only are sea levels changing at a rapid clip, but we have also built a tremendous amount of infrastructure (such as houses, highways, utilities and nuclear power plants) right on yesterday’s coastline.
Not only will the sea level rise itself cause issues, but it is expected to greatly increase the damage from storm surges which will reach farther inland, or overtop natural or man-made barriers that would not have otherwise been breached. This is likely how one would first “get wet” from sea level rise.

7. Sea level rise is not going to stop anytime soon.
With the greenhouse gases currently in the atmosphere, we are already committed to further temperature increases, and further melting of the ice and increasing sea levels. As far into the future as you want to plan for, sea level will probably still be rising. It is something we, and future generations, are going to have to live with. Our climate change actions at this point can slow down the rate of sea level rise and limit the damage, but we cannot stop it.

8. Sea level rise will not be the same everywhere.
There are many reasons why sea level rise might be greater in some places than in others, but in general, when ice melts, sea level rise is less closer to the location of the ice and greater farther away. Differences in the regional heating of the oceans, changes in ocean currents, and a variety of other factors can contribute to regional variations in sea level rise.
In addition, land subsidence, like that occurring along the Gulf Coast of the United States, can worsen the impacts of sea level rise. Land uplift, like that occurring in Scandinavia, can buffer some against future sea level rise.

9. Melting Arctic sea ice does not contribute directly to sea level rise.
The Arctic has a lot of floating sea ice, and it is in the news a lot because it is decreasing dramatically, but sea ice loss in the Arctic does not directly contribute to sea level rise. That’s because it is already floating — it is not on land, so its melting does not directly impact sea level rise. If this sounds strange, you can verify this by watching a glass of ice water and checking the water level as the ice melts — it will not rise or fall. However, if you add more ice to the glass, the water level will rise. (Loss of Arctic ice does directly impact climate change because dark blue ocean absorbs more energy than white ice does, so it adds a bit to global warming).

10. The cost of sea level rise will go up faster than sea level itself.
In other words, the damage caused by going from 1 foot of sea level rise to 2 feet will be much greater than the damage from the first foot of sea level rise. In addition, the cost of conventional berms or levees to protect the shoreline also increases much faster than the height. For example, doubling the height of a levee makes the cost goes up by a factor of almost 4.

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Sea level is already rising fast, but nobody knows exactly how much this could speed up if we continue to warm the earth at the rate we are doing now. One thing we do know is the more greenhouse gases and heat we put in, the faster sea level will rise.
That is why tackling climate change is so important. We have to ask ourselves how much of a chance we want to take. The difference between an aggressive stance on climate change and a slower path could mean the difference between an orderly approach to sea level rise and a chaotic retreat from the coasts.
To read more about how New York and Miami are handling these issues, read our article: A Tale of Two Cities: Miami, New York & Life on the Edge at climatecentral.org.

*Motta has worked in the energy and environment field as a program manager at the National Renewable Energy Laboratory. He is currently an affiliate at the Institute of Arctic and Alpine Research working on the communication of sea level rise risks and impacts.
*White is professor of geological sciences, professor in the environmental studies program, and fellow and director of the Institute of Arctic and Alpine Research at the University of Colorado in Boulder. He is a Web of Science most highly cited scientist (one of the top 1 percent most highly cited authors in his field).
*Nerem is a professor of aerospace engineering Sciences at the University of Colorado in Boulder, and leader of NASA’s sea level change team.

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The Bizarre Self-Harm That Suggests CSIRO Has Lost Its Way

Fairfax - Adam Morton

The treatment of John Church should prompt questions for the Turnbull government.

John Church during his current – and probably final – research voyage with CSIRO. Photo: Supplied

CSIRO's decision to sack the global expert on sea level rise – while he was working at sea, three weeks from shore – is a bizarre form of self-harm that suggests the national science agency has lost its bearings.
Assuming the federal election campaign at some point considers the future of science in this country, the treatment of John Church should prompt questions for the Turnbull government.
Two weeks ago, Church was the co-author of a new peer-reviewed study that found five reef islands in the Solomon Islands have disappeared due to the combination of sea-level rise and high-powered waves.
This is significant not just of itself, but because of what it points to: the area is considered a sea rise hot-spot, with the level increasing up to three times faster than the global average. The study gives an insight into what the future might look like.
A couple of weeks earlier, Church was co-author of a letter published by the internationally respected Nature group that sets out the evidence that humans have been the dominant force in the accelerating increase in sea level since 1970.
I mention these two pieces of research not because of their particular importance, but because they are just the most recently available examples of Church's work, which stretches back to the late 1970s when he was hired by the national science agency after completing a PhD in physics.

CSIRO chief executive Larry Marshall. Photo: Daniel Munoz

In science, peer-reviewed papers carry the weight of gold bars. Church's research – using tidal gauges and satellite data to calculate the pace at which the sea is rising across the globe, and the extent to which different factors are contributing to it – has yielded more than 150.
His CV includes the Eureka Prize for Scientific Research and CSIRO's Medal for Research Achievement. He has twice been a coordinating lead author of chapters in the era-defining reports by the Intergovernmental Panel on Climate Change.
After first being reported by Fairfax Media's Peter Hannam, his sacking was picked up by the New York Times. Its report quoted NASA scientist Joshua Willis describing Church as one of the world's top 10 climate scientists. He summarised: "It is sad and embarrassing for the Australian government."

Illustration: Jim Pavlidis Photo: Jim Pavlidis

Scientists who spoke with Fairfax Media backed this up. They noted Church is conservative and meticulous in his work and public statements. He has often warned against inflated estimates of what can be projected with confidence across this century. He is also a leader, widely praised for his quiet guidance of younger scientists.
To state the obvious, this is not expertise you should give away lightly.
Since CSIRO's plan to axe 275 scientists was announced, Church has been among those who have spoken out forcefully against the cuts to climate programs in particular, arguing they breach Australia's commitment to escalate research as part of the climate deal reached in Paris in December.
Some within CSIRO believe it is likely Church was targeted due to his outspokenness. But it is not clear whether this is the case as CSIRO has signalled it is moving away from investigating global sea level rise.
It is making this cut despite sea level rise being a developing area of science that is clearly in Australia's interest to understand thoroughly.
On average, seas have risen more than 20 centimetres since the late 19th century. The most conservative estimates project a further increase of between 30 centimetres and a metre by the end of this century, depending on greenhouse gas emissions.
This is already having real-world ramifications for coastal planning and existing waterfront infrastructure worth billions. You might think a better understanding of the problem would be helpful to plan properly.
This is also not an argument against CSIRO making changes. It should pivot to focus on areas of science that it believes are most in the national interest. If that includes throwing resources into commercially focused innovation, so be it.
What makes little sense is abandoning areas in which you have world-leading expertise, and where more information is unarguably needed.
Of course, Church's case is just one high-profile example. It is understood 70 scientists in CSIRO's oceans and atmosphere division alone have been approached about a possible redundancy.
It comes as the agency has been scrambling in the face of significant pressure from the scientific community, here and overseas. Chief executive Larry Marshall's response was to spurn an offer by the Bureau of Meteorology to take over some CSIRO climate measurement and modelling, and instead promise to keep a smaller team at a new climate science centre in Hobart, employing 40 scientists.
It sounds good in a press release, but no details are available about how the centre will operate – they are still being nutted out. CSIRO's partner agencies are privately concerned they are being excluded. They believe that to be truly effective the centre should be a national collaboration, bringing in expertise from all agencies and universities. At this stage there is no sign that will happen.
Meanwhile, CSIRO's international reputation is being damaged. A recent Senate inquiry heard suggestions scientists overseas are concerned, and in some cases are crossing it off their list of potential employers.
To date, the government has ducked questions about the CSIRO cuts, citing its role as an independent statutory agency. In truth, the CSIRO act gives the science minister the power to direct the organisation if they choose.
At some point, government ministers should answer the question: do you support the discarding of world-leading scientific expertise that is taking place on your watch?

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Election 2016: Climate Politics Off To A Chilly Start, But Could Still Heat Up

The Conversation - Matt McDonald

Shadow environment minister Mark Butler and environment minister Greg Hunt shake hands before the National Press Club debate. AAP Image/Stefan Postles

One week into the extended federal election campaign, climate has not featured prominently. While prime minister Malcolm Turnbull campaigns on “jobs and growth”, opposition leader Bill Shorten has emphasised education and employment conditions. Climate also warranted no mention in the government’s pre-election budget.
This week’s National Press Club debate between federal environment minister Greg Hunt and his shadow counterpart Mark Butler largely retrod party lines, and received limited coverage.
Yet 2016 could still be a climate election. Here’s why.

Points of difference
There are major climate policy differences between the Coalition government and Labor opposition.
The government has committed to a target of 26% to 28% reduction in greenhouse emissions by 2030 (relative to 2005), and remains committed to its incentive-only auction scheme for industry to reduce emissions.
By contrast, Labor has committed to a 45% reduction in emissions over the same period, with a 50% renewable energy target. It has also pledged to set up an emissions trading scheme that is more consistent with how other countries are approaching climate policy.
These are substantial differences, especially given criticisms that the government’s Direct Action model is expensive and inefficient and offers no guarantee of achieving its stated targets. So there are opportunities for climate to feature prominently as a point of policy difference.

Public opinion
Public opinion tends to move in favour of the opposition on climate policy. For the past several years, the Lowy Institute has polled Australians on climate policy, among other international issues. It has found, perhaps surprisingly, that Australians tend to be most supportive of strong action when the government of the day is perceived as inactive.
The high point for public support was 2006. Conversely, the low point for public support on strong climate action was 2012, as the Labor government under Julia Gillard introduced the carbon tax.
There is evidence now of a rebound in support for climate policy, with perceptions that the government is dragging its feet on climate change. This clearly creates incentives for Labor to campaign on climate.

Green pressure
The Greens loom as a threat to Labor if it doesn’t emphasise its commitment to climate action. The Greens surprised many by winning the lower house seat of Melbourne in 2010, and Adam Bandt has held it since.
Now the Greens have their sights set on other lower house seats, and perception that it is the party that takes climate action seriously will have damaging effects for Labor in electorates most vulnerable to Greens campaigning.
Political opponents of all stripes have a real opportunity to wedge the prime minister on climate change. It appears likely that prime minister Turnbull is playing a long game and hoping that an election victory will allow him to marginalise those parts of his government that still oppose climate action.
This view involves placing weight on the claims Turnbull made on losing the coalition leadership to Tony Abbott in 2009. Then, he declared that he did not want to lead a party not serious about climate action, and questioned any policy that claimed to be cost-neutral. These statements may come back to haunt him.
Finally, civil society groups are mobilising aggressively on climate change. Groups such as GetUp! will be out in force come election day and are promoting climate action, while environmental groups are pushing hard to ensure that climate change will not be forgotten in the election.
Building on devastating reports of coral bleaching and David Attenborough’s most recent television series, many are using the Great Barrier Reef as a symbol of the need to take climate action seriously.

Dangers of a climate election?
For some analysts, Australia’s 2007 contest could rightly be described as “the world’s first climate election”.
The then Labor opposition leader Kevin Rudd rode a wave of support for strong climate action, and took office from a Coalition government perceived as weak on climate change.
In 2013, Coalition opposition leader Tony Abbott declared that the forthcoming election would be a “referendum on the carbon tax”, and in those terms he scored a resounding victory.
In both of these accounts, the role of climate policy in the election result is probably overstated. But it also helps to explain why leaders of both parties appear spooked by the idea of campaigning strongly on their climate policy. It may be easier for Labor to announce its climate position softly, and the government to run a scare campaign on economic costs of any stronger action than its own platform.
Indeed, for some advocates of climate action, a climate election may not be a good thing. The climate consensus that characterises the position of progressive countries has not been reflected in Australia. This undermines policy consistency, economic predictability for business, and public support for climate action.
But it is also the case that Australia’s most recent brief window of bipartisanship on climate policy in 2009 did not end well. The carbon pollution reduction scheme (CPRS) was never enacted. And both the then prime minister Kevin Rudd and current prime minister Malcolm Turnbull lost their jobs, at least partly because of it.
We may well see climate feature prominently in the weeks to come. And while there may be some dangers, it’s hard to think of a climate policy situation in Australia that’s any more problematic than what has come before.

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