Do We Know Enough To Go Messing About With The Climate?

[JackKnife]

http://www.bbc.co.uk/news/science-environment-25639343
Climate is constantly changing, we have only a tiny snapshot of it's history. Is tinkering with a vast complex changing environment wise? Could it do more harm than good?

[beso]

//Is tinkering with a vast complex changing environment wise? //

No. Nor is whacking it by doubling the Carbon Dioxide content of the atmosphere.

Any form of geoengineering is going to cost far, far more than changing to low carbon energy sources.

[Old_Geezer]

I think far riskier things are done today as some push their gung ho attitude.
If one progresses slowly in this area I suspect most things that could be tried could be reversed, which is more than can be said about some gambles taken.

[New Judge]

Well we seem to know enough to suggest that we're causing irreversible damage so I suppose we know enough to try to reverse it.

By the way, beso, since the industrial revolution CO2 concentration has increased from about 300 parts per million to just under 400. Not quite doubled and nothing compared to variations which occurred before that - long before mankind began burning things in any great quantity.

[EDDIE51]

^^ A 33% increase in 200 years when it has been stable for for something like 45,000 years NJ. I think that is pretty significant.

[New Judge]

Yes a fairly significant change, Eddie, but not so serious when considering that it is increasing at about 2ppm per annum and at times in the past the concentration has been as high as 7,000ppm.

[beso]

New Judge //300 parts per million to just under 400. Not quite doubled and nothing compared to variations which occurred before that - long before mankind began burning things in any great quantity.//

The accepted figure for "preindustrial" is 280 ppm so we have already managed a forty percent increase.

I said "double" because, under the "do nothing" strategy, at 2 ppm per year we will have doubled before the end of the this century. If we continue to increase the emission rate (as we have been), we will get there much sooner and just keep going with no end in sight.

What do you think is a sustainable level of CO2 ?

[beso]

NJ // not so serious when considering that it is increasing at about 2ppm per annum and at times in the past the concentration has been as high as 7,000ppm.//

Two ppm per year is the most rapid increase in geological record, perhaps aside from meteor impacts in carbonate strata that triggered mass extinction events.

Do you believe life as we know it will be sustained at 7000 ppm ?

[beso]

I won't bother responding to Dive Buddy's trite answer except to say that the religious attitude is the one that ignores the science.

[beso]

OG // I suspect most things that could be tried could be reversed, which is more than can be said about some gambles taken.//

Exactly. Any geoenginering will have to be continually reapplied.

In contrast, the CO2 increase in the atmosphere is effectively permanent in human time scales. Even if we stopped emitting entirely tomorrow, the effects of the forty percent increase we have already done will be with us for hundreds of generation.

Humanity has never faced such an enormous and irreversible situation.

[jim360]

I'd be wary for the moment about taking any active measures to reverse the concentrations of CO2 or combat the Greenhouse Effect. Far better action, at least for now, would be to reduce the amount we pump into the atmosphere every year and to stop or cut back significantly on other activities that harm the environment. Any active measures do indeed carry their own risks, and the rewards are uncertain. In the last few years we've seen that increasing greenhouse gas emissions don't necessarily translate into consistent global temperature rises. It ought to follow that "anti-greenhouse" materials won't necessarily lower the temperature either, or will lower it at a far greater rate than could have been anticipated.

There is plenty that can be done still before resorting to something like the proposal above.

[beso]

jim360 // In the last few years we've seen that increasing greenhouse gas emissions don't necessarily translate into consistent global temperature rises.//

Not really. There is no doubt that the greenhouse gas emissions lead to long term higher temperatures. The detailed nature of the mechanisms involved over the short term are being steadily elucidated.

For example the so called "pause" in temperature rise is due to heat being taken under in the Pacific Ocean. When the El Nino phase of the Southern Oscillation returns, some of this heat will return to the atmosphere.

Over the long term there can be no doubting that the temperature rise is inevitable f we do not curb greenhouse gas emissions.

[New Judge]

"Do you believe life as we know it will be sustained at 7000 ppm"

I neither know nor care, beso. We've done all this before and in my experience your posts become increasingly abusive and personal, so I'm out.

[jim360]

I suppose I should have clarified that I meant "consistent short-term temperature rises. I don't need to be persuaded of the dangers of CO2 emissions, along with the other unpleasant gases we've been pumping into the atmosphere for ages. I would need to be persuaded that this proposed "cure" isn't worse than the disease in the short-term. It's not really clear that there is any way beyond computer simulation to trial it in a safe way. I think for the time being we should be focusing on reducing our GG emissions and changing other behaviours that supplement the damage GGs can do.

[beso]

I do tend to be critical of those who bemoan the pittance they are asked to contribute towards remediation of the consequences of their consumption, lie about the science and believe that it is fair to leave the mess for future generations.