EarthSky spoke with Richard Alley, a Penn State geologist and winner of a 2011 Heinz Award for his work on abrupt climate change. For the past several decades, he’s been studying ice cores – samples from the accumulation of snow and ice laid down over thousands of years in Greenland and Antarctica.
Taking an ice core sample. Image Credit: USGS
Alley did ground-breaking work in science when he helped extract a two-mile-long ice core from Greenland in the early 1990s, which shows that Earth’s climate changed abruptly in the past. With more of the greenhouse gas CO2 added each year to Earth’s atmosphere, Dr. Alley is worried that abrupt climate change could happen again. He said:
What we expect is that the world will behave itself. As we turn up CO2, the world will get warmer – but we’ll sort of know what’s coming. And we’ll be able to make wise decisions in time to slow down the rise of CO2 and stop it, or whether to adapt to the changes to come. What we’re a little worried about is that we do know from ice cores and other records that occasionally the climate is not well-behaved.
He gave us an example of what he means. Today, climate scientists predict that temperatures will rise a few degrees Fahrenheit in the next hundred years. Ice cores from Greenland show that – around 11,500 years ago – average temperatures in Greenland increased by about 15 degrees Fahrenheit, over the course of 10 years or so. Alley said this abrupt change was prompted – at least partially – by melting polar ice, which altered ocean circulation and weather patterns. As today’s climate warms, ice is again melting near Earth’s poles. Alley said:
So a lot of us are working really hard to get the fundamental physics of how these giant two-mile thick piles of ice flow, how they grow and melt, and how they might behave in the future.
Image Credit: tiswango
EarthSky asked Alley what abrupt climate change would look like if it happened today:
Worst case scenario would be something like changing ocean circulation in a way that made it dry in the monsoon belts in places where people are expecting the rain to water their crops. We know these abrupt [climate] changes in the north Atlantic were accompanied by drought in monsoonal regions, so if we were to trigger something in the North Atlantic, it might, in turn, trigger changes in the monsoon where a huge number of people need the rain.
We’re fairly confident that the Antartic and Greenland ice sheets will stay where they are for at least awhile, but if they were to dump ice in the ocean fairly quickly, you could have very rapid sea level rise.
Alley talked about insurance against that possibility:
Less emissions of climate dioxide, basically. The other thing you look at is trying to build society so it’s a little more resilient. If your planning to build a wall around the city to keep the flood out, maybe you build it a little higher, just in case. For an area prone to flooding or drought, you put a little bit of a cushion in the way you do things, so that if things turn out to be a little worse than we expected, we have an ability to deal with it.
He said it’s not naïve to be optimistic about Earth’s climate future.
There are immense resources out there. The amount of sunlight, wind energy, and geothermal, dwarf the amount of energy that we’re using now, and they’re available with technologies that we have, or that we can get in a fairly straightforward way. If we put our brainpower to work, what we need is supplied by the planet. We can do this. We can grow the food. We can make sure people survive. We can make sure people have something good to do. We can make a sustainable future.
Listen to the 8-minute and 90-second EarthSky interviews with Richard Alley on abrupt climate change, at top of page.
Great article Beth!!
You can see Richard in action (on the Franz Josef Glacier, New Zealand) and down in a crevasse, and at the National Ice Core Lab, in the PBS special he’s presenting, streaming online at earththeoperatorsmanual.com/ Check out his Climate FAQs and you can even see him bungy jumping, helping to illustrate the issues of abrupt climate change and tipping points discussed in Beth’s post. That scene, and much more, will be in the second and third programs, appearing on public TV during April 2012. Check out the website for air dates once confirmed.
Senor Castilla – mutual inspiration club.
Geoff, Thanks so much for the info!
Beth
Petition Presentation, Town of Chapel Hill, NC, November 21, 2011.
Opening remarks…….
In Chapel Hill and around the world, it is all the same: many too many people can be found in too many places destroying the natural world for personal economic gain. Many human-induced pressures on Earth’s finite resources and its frangible ecology, that directly result from the unbridled global growth of overconsumption, overproduction and overpopulation activities by the human species, put demands on the natural world that can overwhelm any efforts to achieve a sustainable future for children, not only in Chapel Hill but elsewhere on the surface of our planetary home. If we are to halt the reckless destruction of Earth as a viable resource base as well as the irreversible degradation of an already polluted environment and a warming climate, we must accept limits to growth.
We must start somewhere soon to chart a sustainable course. Endless economic and population growth appear to be unsustainable. Let us consider now and here ways we can humanely, fairly, equitably and realistically define limits to economic and population growth in Chapel Hill, while there is still time to do so. Once the comfortable and friendly size of Chapel Hill is lost due to economic and population growth pressures, Chapel Hill’s quality of life and special characteristics will be impossible to regain.
Perhaps we can “think globally” about the predicament seven billion human beings present to the viability of Earth as a fit place for human habitation. Then we choose to”act locally” in ways that move us in the direction of a sustainable future for children everywhere and for life as we know it. Thank you.
TO MAYOR MARK KLEINSCHMIDT, MEMBERS OF THE TOWN COUNCIL, TOWN MANAGER ROGER STANCIL AND WHOMEVER ELSE THIS MAY CONCERN on Monday, November 21, 2011:
A Petition to Define Limits to Economic and Population Growth in the Town of Chapel Hill, NC
Whereas the Town of Chapel Hill appears to be outgrowing the comfortable and friendly size that has made it a wonderful place to live, raise children, work and retire; and
Whereas increasing traffic congestion, crime and other social ills are presenting worrisome trends that result from human population growth which will eventually degrade Chapel Hill’s eco-friendly environs, deplete its limited natural resources and conceivably ruin what makes our town beautiful and special; and
Whereas the Town of Chapel Hill has established limits and the Great State of North Carolina has boundary lines that separate it from adjacent states; and
Whereas the USA has borders that confirm the limits of authorized human activity under its regulations and laws as well as distinguish itself as a separate nation; and
Whereas Earth is round, bounded and finite with frangible environs not flat, unbounded and unperturbed by human production, consumption and population activities of the human species worldwide; and
Whereas there are well-known biological and physical “rules of the house” in our planetary home that are categorically different from the manmade laws which regulate day to day production, consumption and population activities of human species, but are no less important to citizens of Chapel Hill, the State of NC and the USA as well as to the global citizenry of the human family, precisely because the biophysical reality of God’s Creation places immutable limits on the unbridled global growth of human overproduction, overconsumption and overpopulation activities; and
Whereas a billion human beings were added to family of humanity worldwide in the last dozen years (1999 to 2011); and
Whereas in the month of October 2011 the seven billionth human being joined the human community; and
Whereas there are more human beings in November 2011 existing on resources valued at less than two dollars per day globally than were alive on Earth in the year of my birth (2.3+ billion in March 1945); and
Whereas we have heard many times, understood well enough, and can reasonably be expected to at least consider acting in a morally responsible way upon a shibboleth of humanity that goes like this, “Think globally, act locally,”
Now, Therefore, It appears appropriate to Propose and Present this brief Summary of a Program for Action.
As a part of the town-wide envisioning process to consciously and deliberately manage economic and population growth in the Town of Chapel Hill between now and 2020, leaders, planners and stakeholders will assure that the maintenance of the unique character and the quality of life in Chapel Hill, as we enjoy it now, is protected and preserved for the children and future generations. To accomplish this goal, various scenarios or different elements of a single scenario will be developed with the hope that the following steps will be examined for their efficacy.
Because overpopulation is ultimately a local issue, set an optimum/maximum population size for the Town of Chapel Hill in 2020. This goal can be fulfilled by adopting growth-management policies related to limits on the number of new residential dwelling units and to additional eco-friendly curbs on commercial developments per year between now and 2020. Zoning regulations can be promulgated to further restrict the size of residential, commercial and industrial buildings within the town limits. The reality-oriented adoption of “soft caps” on economic and population growth will make it possible for the Town of Chapel Hill to sensibly acknowledge and adequately address the considerable and potentially unsustainable growth pressures that are readily visible on our watch.
Steven Earl Salmony
ZPG Now!