Clear and Present Danger: A Conversation With Nobel Laureate Steve Chu on the Risks of Climate Change
By The Climate Community | November 3, 2008 | In: Business, Science, Policy, Media, Social & NGOs
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Dying Forests and Vanishing Water
Another major concern raised by Dr. Chu was water availability, and its effects on human and natural populations. Rising temperatures will stress the global ecosystem that we rely on to supply our water and support the farms that grow our food. Water resources are particularly sensitive to global warming.
Higher global temperatures will cause more vigorous cycling of water between the atmosphere, land and ocean, and, at first glance, one would expect more snow and rainfall. Yet sudden shifts in regional weather patterns are also expected, where droughts will occur in one region of the world while flooding may plague another region. We depend on specific kinds of water to show up at particular times, to support irrigation and fishing, to store water for human use in dry periods, and to keep natural hazards like forest fires to a minimum. Snow in the winter stores water until it melts, providing water for the drier summer months. Extended melt seasons, starting in early spring and continuing through mid-summer, provide water for both fish migration and irrigation. Excess water flows have allowed us to keep some behind dams, providing power generation in addition to irrigation. The delicate balance between hydropower, irrigation, and fish in places like Washington State would turn into a choice: fish runs, agriculture, or electricity?
According to Dr. Chu, climate change could seriously disrupt this fragile relationship between water, seasons, ecosystems, and human activity. Warmer average temperatures would reduce winter snowfall. What snow did fall would melt earlier, due to longer warm seasons. Lower summer water flows would result, since the meltwater would have passed through the rivers in spring instead. And as freshwater rivers dried up, these problems would multiply. Barnett et al (2004) estimated that for a 1-2°C increase in average surface temperatures, the river systems of the western United States would no longer be able to meet demand for water for irrigation, hydropower, and drinking water.
Germans may see decreased water in the Rhine and Elbe rivers, which supply water to the industrial regions of West Germany and the agricultural heartlands of the East.[9] The Sacramento basin, which supports both Central Valley agriculture and drinking water for San Francisco, could see dramatic increases in salinity. In addition to making the water unfit for human consumption or irrigation without expensive pre-treatment, it could also cause the collapse of ecosystems depending on Sacramento River fresh water.[10]
For much of California, water availability is tied to the health of its mountains, and the forests of the Sierra Nevada foothills are already showing signs of dying off as temperatures rise. The carbon equivalent concentration in the atmosphere right now is about 430 ppm. At 550 ppm, some projections suggest that 50-75% of these forests will die.[11] Those forests help guarantee the California water supply, filter carbon from the air, and support the biodiversity of one of North America's largest mountain ranges.
The Sierra snowpack, which supplies water to much of San Francisco and Los Angeles, could decline by 30-70%. Those trees that survive will have different problems. Higher winter temperatures won't kill off as many pests, leaving them better prepared to attack plants again in the spring. The pine forests of the Sierra Nevada mountain range in California have already experienced higher infestation rates from pine beetles, which used to die off during the winter months.
Trees will also become less effective at storing water. Though carbon dioxide is the major man-made cause of global warming, water vapor that naturally exists in the atmosphere stores more heat. As temperatures rise, trees, like the rest of us, will perspire more, releasing more water vapor into the air and storing more heat in the atmosphere. Here is yet another feedback mechanism that will compound the problem of climate change, and make its effects worse.
Rising temperatures will put added strain on those already living in water-poor regions. The destruction of Sierra alpine forests and the loss of Sierra snowpack will end the era of green lawns in Los Angeles and San Francisco. The death of lawns in LA will be followed by the death of agriculture in the Central Valley, one of the most productive agricultural regions in the world. Australia will face additional problems as storm tracks shift polewards and take their rainfall away from what is already the world's driest continent.[12]
Today, roughly 1.4-1.6 billion people lack access to fresh water. By 2050, that number could increase to between 2.9 and 6.9 billion.[13] As access to fresh water becomes more difficult, other pressing problems will become less tractable. The Millennium Development goals, designed to deal with the worst problems of poverty – hunger, education, child mortality, malaria, and environmental stability – are all affected by reduced water availability.
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| 6 - 7 April, 2010 | Chicago | From Shop Floor to Top Floor: Best Business Practices in Energy Efficiency |
| 15 - 16 April, 2010 | Washington, D.C. | Energy and Climate Ministerial of the Americas |
| 1 May - 31 October, 2010 | Shinghai | World Expo (Shanghai) |
| 7 - 10 May, 2010 | Paris | 5th Global Conference on Oceans, Coasts, and Islands: Ensuring Survival, Preserving Life, and Improving Governance |
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Comments feed@Fiona Smythe:
It is funny to note, that those who believe, that the climate crisis springs form overpopulation always seems to think that it is somebody else, who is in excess...
Reducing population is not a project by itself. All studies have shown, that population will regulate itself on basis of the social conditions present, the access to abortion and contraceptives and other demands long advanced by the progressive womens movement.
In Denmark the largest emitter Maersk Aps is accountable for the same emissions as the rest of the country in total. It is obvious that people feel alienated by suggestions, that the climate crisis is their personal fault.
What puzzles me is that a summit like this one is promoting business-based solutions to climate change. Big business have known about these problems for years, but have not changed, politicians have known about this for years but have not reacted. How can we be amazed, that the public seems to view this problem with an apathetic stance?
This is not the time for promoting business based solutions, but for arguing, that the affected parties - the social movements and unions - should take a leading role in the restructuring of society in order to move towards a society not based upon the exploitation of nature.
I implore researchers like Chu to turn their attention towards the movements against climate change, the ordinary people organizing in order to call for a sustainable solution and offer their support to these movements instead of trying to affect politicians and businessmen (and -women) who care only about the profits, that can be reaped from this crisis.
The largest corporations have driven society into a major economic crisis. We can not trust them to solve the climatic crisis, which is just another face of the global crisis of society.
This is an enlightening and disturbing report. I'm pleased that Dr. Chu will be put in a position to address these problems. I'm always surprised, though, that one of the immediate and obvious solutions to the future increase in carbon levels is not mentioned. It seems obvious that reducing the number of people we add to the feedback loop will concurrently reduce the production of greenhouse gases. In addition to technological and behavioral solutions, we should be calling for an immediate, voluntary reduction in the number of children families are having.
We do not, as some people say, need more studies to determine if global warming due to human activity is a reality. Nobody who is not suicidal would seal themselves in their garage with their car running. Why? Because you are introducing toxic compounds into a closed system at an accelerated rate which would result in your death. Our planet is a closed system. A sealed garage. We are introducing at an accelerated rate several compounds that, while not all toxic, could ultimately have a toxic effect if not checked. This is junior science.
We don't need studies, we need action.
Converting to a less toxic economy doesn't mean we need to live like barbarians. We can have all the mod-cons and a healthy planet. There is no harm in this.
On the other hand, the potential harm of the route we are on could spell the demise of nearly all the life on this wondrous planet. Is it worth the risk when all the alternative will cost is cooperative effort?
The reason that many people do not believe the "climate change story" is because many people on the climate change band wagon have twisted the facts and have out right lied about the potential effects of climate change in order to scare them to obtain their support. The fact of the matter is nobody on this plant is really sure what increased CO2 levels will or will not do to our planet's environment, and the truth of the matter is it is the uncertainty that bothers people.
We need to put our efforts in to the science and stop all of the speculation. We need to migrate from I "feel" climate change is going to happen to using the available data for developing our understanding of the potential problem. We can not debate the historical knoweldge that significant climate change has occured on our planet in its history long before humans came along or even existed in large numbers.
There may be natural forces at work in our planets' and/or sun's systems that have nothing to do with us and will occur with or without us. We just need to understand the difference before we start making policy. Scientist have been wrong many times before. Are they right this time? Rarely do we get it right on the first try.
Thanks for this post. I'm reading this after I heard Dr. Chu was appointed head of the DOE by Obama. I'm glad to see Dr. Chu understands global warming so well. A great darkness is lifting in Washington. Obviously, Obama and Chu will need more support from the general population in the US than has been observed to be there so far to do much, but what a difference from anyone in the Bush administration.
The recent reports of methane boiling out of Siberian lakes and methane clathrate outbursts in wide swaths of the Arctic Ocean indicate things may be even worse than Dr. Chu thinks. Methane releases of this type may be kicking off a feedback loop that will make rising carbon dioxide levels look insignificant.