The thing that people do not readily understand is that greenhouse gas emissions accumulate in the atmosphere. The proportion of greenhouse gas, particularly carbon dioxide, in the atmosphere increases, day by day and year by year. What would happen if we could reduce emissions of greenhouse gas by humans today by 50%?
The answer to the question is …not a lot really. There is a majority of climate change scientists who believe that if we are to keep the amount of warming, compared with pre industrial revolution levels, to 2 degrees Celsius or less, then humans have already emitted half the amount of greenhouse gas required to keep warming relatively safe. Cutting the human emissions by half still permits the greenhouse gas levels to accumulate and still has a warming effect on the planet. Even if we were to reduce emissions by 90% today, the climate would still continue to warm.
Now it would be impossible for governments and people to agree to reduce emissions by half overnight or by 90% next year. It would be a tough job to get emissions into a position where the amount of atmospheric greenhouse gases reduces each year.
This does not mean that we should not press ahead with emission reductions, because they will at best slow down the rate of warming and the slower the rate of warming the more easily and less painfully humanity and other life on this planet can adapt to it.
When you look at the levels of greenhouse gas reductions that are necessary and compare those levels with various national and international targets, you will understand that policy makers have set targets that they consider achievable over a time frame that they consider to be relatively painless, rather than setting a target that is aligned with the best scientific analysis.
Most people think that we should mitigate global warming, which is generally (but not wholly) regarded as real, caused by humans and serious. Most people also think that we can solve the problem of global warming.
I am not so sure that we can solve global warming as I suspect that the short term considerations and desires of humanity will always take precedence over the long term considerations. If a problem is in your face then you set about solving it. If the problem is very hard to solve, but not in your face, it can stay in the pending tray until it gets in your face and that is what policy makers are really doing with the problem of global warming.
I doubt if we can stop the planet heating up to beyond 2 degrees Celsius, but we can mitigate its effects and adapt to it. That is the problem that we should take out of the pending tray and start working on, now.
Filed under: carbon dioxide, carbon emissions, carbon offsetting, climate change, global warming Tagged: | amount of emission reduction required to hold global warming at 2 degrees, negative emissions