Wednesday, June 17, 2009

Climate Change

Humanity is warming the Earth. Slowly but surely, we are adding carbon dioxide (and other greenhouse gases) to the atmosphere, and this gas is trapping more and more of the Earth’s outgoing longwave radiation, acting as a planetary blanket. The average global temperature is slowly rising as the Earth attempts to equalize the incoming solar energy (shortwave radiation) with the outgoing longwave radiation. The data and data-model comparisons I have seen on this have convinced me that our actions are influencing the global energy balance. Changes in the sun’s energy input to the Earth system are also part of the equation, but presently this is not the big factor in causing our planet to warm.

This is a political issue, though, because stating that climate change is due to humanity’s actions means that humanity should change the way it does things. There are powerful forces that want to keep the status quo, and so, even though a politician might understand the issue, money and influence could sway this person to speak out and vote against doing anything to remedy the situation. Look at this chart from a recent article in the weekly news publication, Eos, citing a 2008 Gallup poll that asked the question, “Do you think human activity is a significant contributing factor in changing global mean temperatures?”:

The also asked the survey responders about their level of scientific involvement in the subject, and the graph partitions the results accordingly. Those actually in the field have reached an overwhelming consensus that human activity is a significant factor in changing the Earth’s temperature. Nearly 40% of the general public, however, believes that human activity does not significantly influence temperatures. There is a large disconnect between those who are studying this issue and the rest of us. Why? Of course, there is always a disconnect between the scientific community and the general public, but for this issue, it is complicated and intentionally obscured by those with a financial or political interest in doing nothing to alter our course.

There is actually good reason for skepticism. The timescales are long and the predictions are uncertain. Plus, there are politicians who overemphasize the dire consequences of inaction (e.g., Al Gore) and, while they are helping to raise awareness of the issue, they stir the political backlash. Two things are clear to me, however: we are largely responsible and we need to begin the process of reducing our greenhouse gas emission rates immediately.


  1. If we take a pretty conservative view and say that, yes the atmosphere is getting warmer, and yes, sea levels are going to rise ~significantly~ over the next 100 years, then there are real dire consequences to the human population. Even is ~significantly~ is 1 meter, that is huge, and something like a billion people will be affected. Now, most of those people are not in the US, so, we don't really care about them, but we probably should.

    The sad thing is that humans really can't think in these terms. We have a hard enough time realizing that drinking and driving don't mix - how can we convince people that driving will cause the death of possibly hundreds of thousands of people 10s of years in the future. The lines are too hard to connect for most people. So, they ignore it. And eat at McDonalds. And get fat. And smoke. And drink. And don't exercise.

    Do you want to hear a sad, sad story? I am sitting here in a hotel room in Denver, CO, after flying across the country to attend a meeting for 5 hours on doing model runs for climate modelers. If you take the carbon footprint of this meeting, it would be insane. Even the people who fully understand the problem are not following the advice. We even talked about including aircraft emissions in the models. Nice.

  2. Wow, that ranks right up there as one of the saddest stories of the week.

    Now just think about all of the plane flights involved with ~2000 people from around the world writing an IPCC report. Sad.