Ignored Climate Science

Often ignored but essential aspects of global climate science explain why today's global warming of 0.78ºC is actually twice what we think it is.

Today's level of greenhouse gases in the atmosphere totally
commits the world to a warming of at least 2ºC by 2100
(confirmed by computer models, 2007/2008).

Here's the explanation.

1. The top three GHGs are, in their effect, highly persistent and cumulative.
• Carbon Dioxide (CO2) - 20% of all CO2 emissions last a thousand of years in the atmosphere after emission. (It is generally given a lifetime of 200 years average, which underestimates its effect, especially with levels still rising at an accelerating rate.)


• Methane (CH4) - After its 12 year lifetime of high heat forcing, methane is converted to other GHGs, notably CO2. Therefore some of the heating from methane emissions will last for a thousand years. Another nasty thing about methane is that the higher its concentration gets, the higher its heating capacity becomes. So a higher methane concentration heats more — and then some.


• Nitrous Oxide (N2O) - Lasts 120 years in the atmosphere, over which time its heating capacity is 300 times that of CO2.



Figure 1: As we delay longer in reducing our GHGs, the time it takes for GHG levels to fall in response to a reduction stretches out
much further and further.




2. The committed global warming today is more than double today's temperature increase.
• Today's warming is 0.78ºC. This is the temperature increase since 1900 (beginning of the industrial era).


• The global warming temperature increase is calculated by averaging the global surface "land-sea" temperature over a year.


• The temperature increase inland is up to double the global average temperature increase.


• The heat absorbed by the ocean is circulated around the planet, so at any time there is latent heat content in the ocean that is not yet being registered at the surface.


• There is another 0.6ºC "in the pipe" due to the OCEAN HEAT LAG.


• 0.78ºC + 0.6ºC = 1.38ºC.





Figure 2: What's in the pipeline? (IPCC)




3. Global warming of 1.38ºC is extremely dangerous — and far too dangerous — but it won't end there.
• Assuming that today's adults are not planning to leave their children and grandchildren a planet that is wrecked and beyond all hope, then one must factor in the additional warming caused by a time lag that will occur even if humanity mitigates immediately with all its might. Will it take 10 years or 20 years to convert the planet from fossil fuel energy to renewable energy?


• James Hansen assumes another 0.6ºC of warming during this timeframe, which gives 1.98ºC.


• In other words, this and all future generations are at 2ºC global warming today, and that is catastropically dangerous global climate change. In fact, the models are now telling us that we can't avoid going over 2ºC. The question now is how far over and for how long.

We should be saying that WE (humanity, life on Earth) are already at +2ºC as this is the reality we should be addressing.





Figure 3: Time lag to reach equilibrium



4. Global warming, climate change, sea level rise and ocean acidification will last over a thousand years (S. Solomon et al, 2009).
• As a result of the persistence of GHGs in the atmosphere, the Earth will not cool for over a thousand years after GHG levels have been stabilized.


• The sea level rise continues for thousands of years, as does ocean acidification.



5. The real world impacts of global warming and climate change will be additive and synergistic combinations and effects. The damages will be cumulative over time.

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