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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Feeding Ourselves on a Warmer Planet
Of course, Dr. Chu was quick to remind us that a decrease in water availability means more than dying lawns and shorter showers. Water issues go hand in hand with food issues. All these changes will have serious impacts on the way we feed ourselves. Some climate skeptics suggest that global warming could be good for world hunger – think of all the cold parts of the world that could now grow food!
Unfortunately, the research suggests otherwise. Crop yields are very sensitive to changes in growing season length and temperature. Crops depend on irrigation, which in turn depends on the availability of fresh water.
But the problems of food supply in the face of global climate change go beyond even these serious issues. The effects are complex; plants benefit from rising levels of carbon dioxide, but those benefits appear to be offset by rising temperatures. Plants certainly consume carbon dioxide as part of the photosynthesis process. But, as temperatures rise, plant photosynthesis becomes less efficient. Scientists are still learning more about how these effects balance each other.
Plants also respond to temperature stresses with built-in survival mechanisms. They may reduce their size, their rate of growth, or their production of the fruits, grains, and seeds that humans use for food. These effects appear to be much worse at the lower latitudes where most developing countries – those most sensitive to changing food supplies - are found. In the 2-3°C range, estimates place grain crop yield losses at 0-15%, depending upon the success of adaptation.
For developed countries at higher latitudes, grain yields may rise or fall by up to 5% depending on adaptation.[14] Much above a temperature change of 3°C, however, crop yields decline rapidly across the board. Some recent research suggests that in the most conservative of the IPCC temperature scenarios, yields of crops like corn and soybeans could fall by as much as 30-40%.[15] Worse, higher summer temperatures also increase the chances of crop blights.
Furthermore, rising temperatures bring with them a rising frequency of extreme weather events - droughts, high-temperature days, stronger storms, flooding, and heavy short-term precipitation. The stresses these events place on the agricultural system as a whole put crops and food production at risk. Droughts reduce water availability and threaten crops that depend on irrigation. Storms and floods can damage or destroy crops, as the residents of the Mississippi Basin found during the summer of 2008. Heavy precipitation erodes cropland. Cumulatively, these effects have the potential to strain the world's food supply over the next century.
Economic development is helping more and more people get access to stable, plentiful food; climate change could reverse some of those gains, leading to an additional 40-170 million people at risk of hunger by the end of the century. More and more of these people will come from regions already at risk of hunger. Food supplies in sub-Saharan Africa, already one of the world's poorest regions, will become even more unstable than they are today.
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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.