Dear Sir:
A growing and developing population is likely to increase their greenhouse gas (GHG) emissions (expected to double by mid-century), not so severely cut them so fast as to avoid runaway global warming.
Nature now soaks up about half of mankind's CO2 emissions, but that is expected to reduce 30% by 2030. Furthermore, as the world heats up, carbon sinks will become carbon emitters.
In other words, whatever reasonable cuts we can expect mankind to make in their GHG emissions, they will be overwhelmed by nature.
In particular is melting methane hydrate. Incredibly, hydrate contains twice the carbon of all fossil fuel, and whereas fossil fuel needs to be burned to emit GHG, hydrate needs only to melt.
Briefly, carbon in the soil is "eaten" by microbes, and in the absence of oxygen the microbes emit methane (CH4). Some of that methane gets trapped in ice called hydrate.
There is about 400 billion tons of methane trapped in permafrost hydrate (20% of the land on earth is permafrost). 50% of the surface permafrost is expected to melt by 2050, and over 90% by 2100.
A release of less than 30 billion tons of methane would be like doubling the CO2 in the air.
Worse, there is an estimated 10,000 billion tons of methane hydrate under the ocean. Substantial quantities of this has melted before with catastrophic results (55 million years ago -- the PETM ushered in the Age of Mammals, and 250 million years ago -- the "Great Dying" killed most life on earth).
In other words, the carbon cycle has been upset before (possibly by volcanic eruptions), causing a chain reaction. Mankind's GHG emissions are over 30 times stronger a trigger than past severe runaway global warming events. This means the chain reaction will happen sooner, unfold faster, and therefore be much, much more severe.
And some suggest adaptation?
To summarize, the mitigation strategy of human GHG emission cuts is implausible, because soon runaway global warming makes them too little, too late. Furthermore, past runaway global warming events make adaptation implausible, because the climate change is too severe.
Therefore, the only solution is to remove the CO2 from the air after it has been emitted. Nature already does this but we are overwhelming her ability to cope.
I suggest improving nature's ability to absorb CO2 with genetic engineering (perhaps seeding a genetically modified organism into the ocean).
Brad Arnold
Saint Louis Park, MN
USA |
