The latest IPCC report's "summary for policymakers" on climate change came out a few days ago. I downloaded it and have been working my way through it. You can download it for yourself from the IPCC's main website (look under "The AR4 Synthesis Report" mid-way down the page). Given that many have criticized this latest IPCC report for perhaps not being bold enough, it is quite striking how serious the projected outcomes and scenarios are. (It also does a good job of demonstrating the human contribution to global warming, by the way, with helpful pie charts of greenhouse gas [GHG] contributions from various sources, continental temperature trends, etc.) I'm sure there will be more insights to come from this report--and I encourage readers to comment on them here--but I would like to focus on just one thing that caught my eye. I noticed under "Examples of some projected regional impacts" (p. 10), that some noticeable effects on food production are expected ALREADY BY 2020. While most effects, in all areas, are negative for human welfare, there are some exceptions. For example, while Africa is expected to see 75-250 million people under water stress and up to a 50% reduction in rainfed agriculture by 2020, in that same period the rainfall-based portion of North America may actually experience short-term increased yields of 5-20% in the aggregate due to warming. This inequitable pair of outcomes seems especially cruel and ironic given that we North Americans have been far greater contributors to global warming than most Africans. Of course, even North America is expected to face some problems in the short term, such as droughts and decreased mountain snowfall (the main source for irrigation-based agriculture) in the West--not to mention heat waves, coastal impacts, and health consequences. But I find it a great tragedy that the poorest (and lowest GHG emitting) regions of the world may suffer the most, just when the need for action will be greatest in the industrialized world. I had heard about this before, but it was sobering to see it spelled out in the IPCC report summary.
Over the long term, of course, the consequences seem quite unequivocally dire for the entire planet, if dramatic action is not taken. I hope that we can all remember during this holiday season the natural world that we have (as a gift from God, if you are religious, like me) to be caretakers of. Maybe for this Thanksgiving, we should give thanks that our planet can still support human life.