depleting fossil fuels
Posted by Laura McLay on February 10, 2009
My family is just now recovering after 2+ weeks of battling a nasty virus )-: I missed blogging. I have something interesting to write about today.
Yesterday afternoon, I attended a talk by Dr. David Carlson (inventor of the amorphous silicon solar cell in 1974, currently at BP Solar) about the depletion of our fossil fuels, global warming, and solar energy. In the talk, Dr. Carlson guided us through the fossil fuel controversy, and encouraged us to think about photovoltaics and solar power.
Although I know little about peak oil, I’ll explain it how Dr. Carlson explained it in his talk, focusing on modeling. Oil discovery has been declining, and even the oil companies forecast declines. After oil is discovered, oil production ramps up, peaks, and then declines as the oil is depleted. Production peaks 25-45 years after discovery. Oil production peaked in the US in the early 1970′s and has been declining in North American (US + Canada + Mexico). Oil production has been leveling off in the Persian Gulf by some estimates. Has worldwide production already peaked? It may have. Based on (1) oil discovery and (2) oil production, many experts predict that the total worldwide oil production will peak between 2010-2020, but there is a lot of variation.
There are a few wildcards in these peak oil predictions:
- Unconventional oils could be widely used soon (decreasing demand for conventional oil), but it is possible that these will make even more carbon dioxide than conventional oil.
- All peak oil estimates depend on predictions on growth of the world economies.
- Cheap alternative energy sources could also make a splash, changing oil demand.
The bottom line is that predicting peak oil depends on several forecasting models (oil discovery, oil production as a function of discovery, oil demand, world economies growth). Each forecasting model has large error bars, and combining the sources of error doesn’t exactly make the predictions any easier (forecasting is tough!). But we are sure that (1) the planet is getting warmer and (2) we use a lot of oil, (3) our oil won’t last forever, and (4) carbon dioxide hangs around in the atmosphere for decades, so we need to do something now. It bothers me that the talking heads have been talking about peak oil forecasts as if they were certain, because the variance in forecasting estimates are generally very large.
Dr. Carlson also talked about how global warming is measured. It isn’t easy. All measurements have large error bars, and thermometers haven’t been around for very long. In addition, although the average global temperature is increasing, it is not increasing everywhere at the same rate. Arctic temperatures have risen much faster than the rest of the planet, resulting in fast melting of the the ice caps.
Measuring changes in sea level is also difficult. Using tide gauges is problematic, since you cannot assume that land level is a constant frame of reference over long periods of time. Satellites are currently used to measure temperatures and sea levels.
I am sure that many of you know more about these issues than I do, and I apologize about any errors on my part. Please leave a comment if you want to add something!