Integrated Impacts of Climate Change

Climate Policy Interface: All the Impacts Together

In the last two blogs, I wrote about which impacts of climate change might or might not accelerate the formation of policy. One of the points I was trying to make is that taken in isolation, an issue such as the impact of climate change on agriculture might seem “manageable.” We have many strategies for addressing agricultural problems, managed irrigation, multiple crop choices, the ability to hybridize, perhaps even genetically modify seeds. Again, in isolation, we have strategies of engineering, policy, and technology that allow us to develop a strategy to adapt.

Another point that was, at least, implicit: There are a number of ways to look at an impact. One might be in an absolute sense; that is, what are the direct impacts of climate change on, say, the ability to water crops in eastern Montana? Or northern Argentina? Another way to look at the problem is based on economic impact. The point was that while the impact might be very large locally, in the aggregate across all of the economy, the impact may seem smaller. We can trade and adapt.

In the field of climate change there is a type of model called the integrated assessment model. The ambition of these models is to evaluate the impact of climate change on multiple sectors of the economy; for example, the models produce estimates of greenhouse gas emissions; the impact on agriculture of both climate change and our decisions on biofuels. This is, obviously, an enormous task, and it is not based on a physical system as well defined as the climate. Integrated assessment models are one of the tools that motivate thinking about policy; they are a tool to understand balance of policy options.

The question I originally posed was: What are the impacts that might motivate the development of policy? Usually the first time I pose this questions the answers are agriculture, public health, ecosystems, and water. When posed after some discussion, the answer is often national security caused by international instability, which comes from the integrated impact on economies and dislocation of people. The dislocation of people is largely related to sea level rise.

The other issues are climate change turning into economic opportunity, the legacy that we leave for our grandchildren, and water.

The predictions that the average surface temperature will rise and that sea level will rise are robust. We will have to adapt to this. There will be disruption. The question arises about whether or not we can develop and pursue an effective mitigation policy remains open.

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