Essential Linkage: A new study shows that we are not, in fact, in immediate danger.
Global Warming is one of those buzzwords you hear bandied around newspapers and television channels every year or so, as new evidence that it's going to kill us all and be a Very Bad Thing™ surfaces - but you don't hear much about the counter-argument. Ignoring the current fact that the Sun is in a low-power phase, Global Warming is caused by a significant increase in Carbon Dioxide (CO2) in the atmosphere, essentially causing a Greenhouse Effect where heat energy from the Sun can enter the atmosphere but finds it difficult to leave.
Just a five degree Celsius increase in global temperature would be more than enough to significantly disrupt the fragile ecosystems and habitats of a huge amount of the animals and plants we have on this blue/green ball we call home, and amongst other fun things the oceans would also absorb more CO2 as temperatures increased, becoming acidic in the process.
This has just recently been highlighted as old news however, as a study explains:
The Palaeocene-Eocene Thermal Maximum (about 55 Myr ago) represents a possible analogue for the future and thus may provide insight into climate system sensitivity and feedbacks. The key feature of this event is the release of a large mass of 13C-depleted carbon into the carbon reservoirs at the Earth's surface, although the source remains an open issue. Concurrently, global surface temperatures rose by 5-9 °C within a few thousand years.
Now while this seems to have happened 55 million years previously, the heating and carbon dioxide process seemed to take a few thousand years - what is spooking most scientists is that the levels are increasing incredibly rapidly comparatively. Arstechnica explains the findings quite well, describing how we're currently at a "280ppm to 390ppm" level of CO2 (where ppm means quite literally parts per million), and the atmosphere 55 million years back was at "atmospheric CO2 levels from 1,000 parts-per-million up to 1,700 ppm".
The original source of CO2 55 million years back is unknown, but it's not too much of a stretch to extrapolate that at the rate we're burning fossil fuels and forests that we'll be getting close to the 1000ppm levels and into the zone where temps are going to soar. Conditions have changed since the past, and while it can only serve as a rough guide to us it's definitely a very likely circumstance to find ourselves in once again - it'll just take a while to get there.
Head to Arstechnica to read more on the new study, as the discussion about the truth of Global Warming marches on.
Issue: 107 | December, 2009