Global warming is here to stay there is no denying that. If we continue at the rate we are going at the moment, the temperatures on Earth are going to be as hot as they were in the Eocene. Eocene is a period that came some 15 million years after the dinosaurs went extinct. This means that we might have the same temperatures by the end of this century as we did 50 million years ago. This is an increase that is somewhere between 16F and 25F above the temperatures we have now.
The fact that the temperatures were hotter during the Eocene period is something that the climate change doubters often use as evidence that climate change is not caused by human activity on Earth. And there is some merit to what they are saying if you observe things superficially. A million years ago, the American Midwest was covered in glaciers, and some 50 million years ago crocodiles roamed the plains of Greenland. But this was all before the increasing amounts of CO2 and other greenhouse gases were released into the atmosphere. Even their name, greenhouse gases, is derived from the fact that they can magnify the energy of the sun.
During the Eocene period, the sun was not as hot as it is now, and a lot more atmospheric CO2 was needed to influence the surface temperatures. But what many people do not know is that our sun is only getting hotter with age. The combination of a warmer sun and rising CO2 levels means that by the year 2100, the temperatures may be on par with those during the Eocene. The higher temperature coming from the sun means more energy is trapped beneath the greenhouse gas clouds.
It is true that the temperatures were higher before and that CO2 was present in large quantities in the past. But the whole process of increasing temperatures took a whole lot longer since the sun was dimmer at the time. With the rising temperature of the sun and the increasing amounts of CO2, that process is a lot quicker now.
If we continue to use our fossil fuels like coal and gas at the rate at which we are going now, the amount of CO2 in the atmosphere is going to rise to around 2000ppm by the year 2250. Those levels of CO2 emissions have not been recorded on Earth for over 200 million years. This in combination with the hotter sun is also going to raise temperatures to levels not recorded in the last 420 million years, a period which predates even the dinosaurs.
Around 400 million years ago there was a decline in the amount of CO2 emissions because the heat coming from the sun increased and that in turn increased the rate at which biochemical reactions started occurring on Earth. The natural way in which CO2 emissions are controlled is called silicate weathering. This process occurs when rock is broken down into soil. This process is as much temperature as at is runoff dependent. This means that the rate at which it happens depends on how wet and warm the atmosphere is.
And the fact is that this process is going to speed up due to the increased levels of CO2. But this is still not enough to make a significant change. The situation has gotten to the point that even if we stopped emitting CO2 this instant, it again might take more than a million years to clear up the traces of our emissions. And even that might not be enough. So, if we are ever going to make a significant change, it should be now.