The Climate Change Thread
THis topic ALWAYS comes up, and I have not seen a legitimate thread here for this topic.
THere seems to be some debate (mostly from americans in my expeience) that climate change/global warming is not man made, or at least influenced by our way of life.
Unfortunately, the vast majority of the scientific community does not deny this, or deny our activities are influencing the climate. Every few months there is more date being shown which explains our role.
Every lifeform on this planet influences climate. From squirrels planting trees, to cicada mass birth and death influencing soil fertility. This also goes along with natural climate fluctuations due to the earth axis, sun activity and geological features.
The last ice age was caused by the tilt of the earth axis. The PETM was caused by run away warming enabled from geological movement, and unlocking frozen methane deposits, causing the ocean floor to reach 20C (about 60F). The cretaceous was a time of great climate upheaval due to the indian subcontinent slamming into asia, and the rise of the rocky mountains, causing the inland sea in NA to drain. Well before that, there was the greatest exinction event at the end of the permian. There was a 95% extinction rate due to a basalt eruption which turned most of siberia into a giant volcano. This again caused methane deposits to melt quick causing a massive die off and warming.
Now there are some similarities between climate upheavals. Extinctions, less or more precipitation, dry land turning wet, and vice versa, "permanent" ice melting and fluctuating as well as rising water levels.
Now lets look at the present....
Humans have cut down roughly half the worlds forests, and they are now either a prarie/savannah type habitat, farmland or cities. The vast majority of forests are now secondary growth, which do not absorb and process C02 levels as well as primary forest. A good portion of the "filter" is gone due strictly our activities.
There is also the obvious correlation between our population rise and the use of fossil fuels, and recorded temp rises. These days out Co2 emissions are going hand and hand with directly measured co2 levels.
This is when I usually hear people scream (co2 was higher in the past, whats the danger?). Well the last times CO2 levels went up this fast, they melted methane deposits in the oceans creating even more warming, faster. Once methane starts to melt (like it has) there is almost no stopping the warming trend. Carbon 14 (methane) is something like 10 times more effective as a greenhouse gas. Before the rise of oxygen, it is thought methane warmed the planet billions of years ago before the rise of photosynthetic organisms like cyanobacteria or stalagtites.
Has the planet seen worse run away climate change in the past without human influence? Of course. Does this mean its impossible for us to influence and even change the climate? No, because the signs are already there.