(02-25-2019, 02:38 AM)Thoreauvian Wrote: Present human-caused climate change is progressing about 100 times faster than warming periods during natural climate change, according to the experts. The rate alone is one of the biggest threats that face us.
No it isn't. From 1600-1800 (coming out of the "little ice age") the world warmed at a rate of about 0.3°C per century. 1900-2000 the world warmed at a rate of 0.6°C per century. 2000-2100 projections are around 2-4°C per century. So that's about a rate of 6.7-13.3x as fast as that one example of natural climate change. One full order of magnitude lower than you just claimed.
Quote:I did answer you about what natural forcing agents are doing in the present in the following paragraph:
There are only so many possible causes of climate change. The continental drift and massive volcanic eruptions of millions of years past are no longer possible explanations. Recent volcanic eruptions increase greenhouse gas emissions less than 1% of the total observed. Orbital variations work on much longer periods of time. Solar output has not increased significantly since 1979, when NASA began to monitor it using satellites. The usual small variations in solar output on an 11-year cycle is not a trend upwards. Only the greenhouse gases accumulating in the atmosphere can explain present climate change, and they are responsible for almost all of it. Other hypotheses, like the tenuous relationship between clouds and cosmic rays, must still explain why greenhouse gases do not produce the warming expected. Greenhouse gases alone are a sufficient explanation.
Present human-caused climate change has delayed the next ice age by an estimated 130,000 years. From post #100: However, as climate scientist James Hansen pointed out, “Forces instigating ice ages ... are so small and slow that a single chlorofluorocarbon factory would be more than sufficient to overcome any natural tendency toward an ice age.”
In fact, I could answer all of your questions since I have already done so in previous posts. But I am tired of your attitude toward what scientists tell us -- that climate science is extremely complex and can't be summed up quickly. So believe whatever you want, however ill-informed.
I am not disputing that CO2, Methane, and Black Carbon contribute to climate change. Let's assume a conservative estimate of 2°C warming from 2000-2100 will occur, let's assume it's 100% anthropogenic to those three things. Australia contributes 1.3% of global anthropogenic GHGs - right do we agree about that? So if we cut ALL our emissions then at most we can reduce climate change by 0.026°C by 2100. That is an unmeasurable difference - the difference we make according to current climate science is so tiny that it can't be measured. So please explain to me - what is the point of us spending stupid amounts of money to cut emissions when it will make no difference to global temperatures?
Let me reiterate - we could double our GHG emissions in Australia over the next 100 years and you would not be able to measure the difference it makes to global temperatures. That's assuming the science is as reliable as SYZ seems to think it is.
