Climate Change: The lost generation, and possibly much more

Try this:

There’s a ‘big gorilla hiding the closet’ whose collapse could have a dramatic effect on sea levels, according to Australian researchers.

Dr Bradley Opdyke, a paleoceanographer from the Australia National University (ANU) believes the West Antarctic Ice Sheet (WAIS) could partially collapse within 20 years, resulting in a dramatic jump in sea levels.

His talk on glacial cycles and the WAIS was presented earlier this month at the Imagining the real: life on a greenhouse earth conference held in Canberra.

“The 900-pound gorilla hiding in the closet is Antarctica. We have evidence that it is not a stable beast,” Opdyke says.

He says the WAIS is inherently unstable, and the current rate of sea level rise is placing it at risk.

“It is pinned on the spines of a few mountains, with ice sheets draped off them,” Opdyke says. “If sea level rise unpins these sheets, it is plausible that there will be dramatic ice collapse in the West Antarctic.”

See the article for the facts behind that conclusion that the WAIS “is not a stable beast.”

And why 20 years? As many of you probably know, Monday was the 20th anniversary of the now-famous testimony by James Hansen before a US Senate committee which happened to include a Senator from Tennessee named Al Gore.[1]

Hansen gave a talk on Monday, Global Warming Twenty Years Later: Tipping Points Near [4 page PDF] to the National Press Club, which began:

My presentation today is exactly 20 years after my 23 June 1988 testimony to Congress, which alerted the public that global warming was underway. There are striking similarities between then and now, but one big difference.

Again a wide gap has developed between what is understood about global warming by the relevant scientific community and what is known by policymakers and the public. Now, as then, frank assessment of scientific data yields conclusions that are shocking to the body politic. Now, as then, I can assert that these conclusions have a certainty exceeding 99 percent.

The difference is that now we have used up all slack in the schedule for actions needed to defuse the global warming time bomb. The next President and Congress must define a course next year in which the United States exerts leadership commensurate with our responsibility for the present dangerous situation.

Otherwise it will become impractical to constrain atmospheric carbon dioxide, the greenhouse gas produced in burning fossil fuels, to a level that prevents the climate system from passing tipping points that lead to disastrous climate changes that spiral dynamically out of humanity’s control.

Changes needed to preserve creation, the planet on which civilization developed, are clear. But the changes have been blocked by special interests, focused on short-term profits, who hold sway in Washington and other capitals.

I argue that a path yielding energy independence and a healthier environment is, barely, still possible. It requires a transformative change of direction in Washington in the next year.

A bit later on:

Climate can reach points such that amplifying feedbacks spur large rapid changes. Arctic sea ice is a current example. Global warming initiated sea ice melt, exposing darker ocean that absorbs more sunlight, melting more ice. As a result, without any additional greenhouse gases, the Arctic soon will be ice-free in the summer.

More ominous tipping points loom. West Antarctic and Greenland ice sheets are vulnerable to even small additional warming. These two-mile-thick behemoths respond slowly at first, but if disintegration gets well underway it will become unstoppable. Debate among scientists is only about how much sea level would rise by a given date. In my opinion, if emissions follow a business-as-usual scenario, sea level rise of at least two meters is likely this century. Hundreds of millions of people would become refugees. No stable shoreline would be reestablished in any time frame that humanity can conceive.

…

The disturbing conclusion, documented in a paper I have written with several of the world’s leading climate experts, is that the safe level of atmospheric carbon dioxide is no more than 350 ppm (parts per million) and it may be less. Carbon dioxide amount is already 385 ppm and rising about 2 ppm per year. Stunning corollary: the oft-stated goal to keep global warming less than two degrees Celsius (3.6 degrees Fahrenheit) is a recipe for global disaster, not salvation.

These conclusions are based on paleoclimate data showing how the Earth responded to past levels of greenhouse gases and on observations showing how the world is responding to today’s carbon dioxide amount. The consequences of continued increase of greenhouse gases extend far beyond extermination of species and future sea level rise.

Arid subtropical climate zones are expanding poleward. Already an average expansion of about 250 miles has occurred, affecting the southern United States, the Mediterranean region, Australia and southern Africa. Forest fires and drying-up of lakes will increase further unless carbon dioxide growth is halted and reversed.

Mountain glaciers are the source of fresh water for hundreds of millions of people. These glaciers are receding world-wide, in the Himalayas, Andes and Rocky Mountains. They will disappear, leaving their rivers as trickles in late summer and fall, unless the growth of carbon dioxide is reversed.

Coral reefs, the rainforest of the ocean, are home for one-third of the species in the sea. Coral reefs are under stress for several reasons, including warming of the ocean, but especially because of ocean acidification, a direct effect of added carbon dioxide. Ocean life dependent on carbonate shells and skeletons is threatened by dissolution as the ocean becomes more acid.

Such phenomena, including the instability of Arctic sea ice and the great ice sheets at today’s carbon dioxide amount, show that we have already gone too far. We must draw down atmospheric carbon dioxide to preserve the planet we know. A level of no more than 350 ppm is still feasible, with the help of reforestation and improved agricultural practices, but just barely – time is running out.

Hansen then talks about public policy, and taxing carbon, but with the stipulation that 100% of the money is refunded to taxpayers, thereby giving everyone a strong financial incentive to use less fossil fuel. (I’m still pondering this one, and don’t have a strong opinion yet.) He also mentions the need for a vastly better electricity grid to better support decentralized renewable energy sources, something I couldn’t agree with more.

You can also see some “related” presentation slides [44 page, 2.9MB PDF] and his web site. I strongly recommend the presentation, as it provides some technical background on CO2 levels, what’s happening to Greenland, etc.

So, what is the point here? Sadly, it’s not merely a matter of having lost time, so that when we do finally get off our collective asses and start working to reduce CO2 emissions it will cost a bit more. Like that other monster under our bed that’s growling ever louder, peak oil, we’ve delayed to the point where the remedies will be exceedingly, and needlessly painful. Ask the coal plant operators how they will deal with CO2 emissions restrictions/taxes, or the airlines and car companies and mainstream consumers how they’re dealing with $136/barrel oil. All indications are that over the next 5 to 10 years those situations will get far worse as the price of oil continues to rise and our awareness of the urgency of global warming grows.

The saddest part of this quickly compounding mess is that the people who will have to do nearly all of the heavy lifting are today’s children and those yet to be born. Those of us who are today adults, and those who came before us over the last two hundred years, have built a world that includes many genuine wonders, but at a horrific price; the accumulated cost of our energy use has been far higher than all but a tiny sliver of the general population realize. By ignoring the warnings of people like James Hansen, Al Gore, Bill McKibben, Ross Gelbspan, and many others over the last 20 years, we’ve thrown away the opportunity of that generation and forced the next few generations to live with a nearly suffocating burden.

None of us should consider giving up, though. There’s still plenty of time for us to help ourselves and our children[2], to begin the process of stepping back from the brink. We can educate ourselves and each other, make more enlightened decisions about the myriad of goods and services we consume, and become more active in politics at all levels to force our elected representatives to do the right things. It’s time for us to turn our backs on the easy myopia and willful ignorance of deniers, recognize the breadth and depth and urgency of these problems, and act like responsible, compassionate adults.

[1] This is not to imply that this hearing is what turned Al Gore green; he saw the light long before 1988.

[2] And yes, they’re all our children, whether or not they share our DNA.