How can that be? Isn’t any improvement better than none? Unfortunately no. The idea that even curbing some greenhouse gases must be better than none reflects a fundamental lack of understanding of tipping points and positive feedback loops.
The rising level of CO2 in the atmosphere is common knowledge. Increased CO2 raises global temperature. CO2 was 200 parts/million (ppm) in 1800 and it has now topped 400 ppm. NASA reports that as of 2014, average global temperature had risen 1.2 degrees Fahrenheit, or .8 Celsius, since 1880. To make matters worse there is a 30-year delay in the full effect of CO2 on temperature. That means the current global temperature increase only reflects CO2 increases through 1985.
Extrapolating in a linear manner from this rise misses how climatic change occurs. The reason the Paris climate conference last December set a target of holding global temperature increase to 1.5 degrees Celsius is because the best climate change model projections show that once we cross that marker, we hit a tipping point. This triggers positive feedback loops that create further increases; once initiated these increases cannot be stopped.
The most widely known of these loops is the melting of Arctic Sea ice. Until recently the white Arctic ice cover reflected heat back into space, reducing the effect of the polar summer sun. Now that so much ice has melted, the exposed darker seawater absorbs the heat of the summer sun instead of reflecting it. This causes additional heating, inducing more ice melt, causing more absorption and heating. This positive feedback loop is why Arctic temperatures are rising so rapidly and melting Greenland’s ice sheet. If not reversed, this positive feedback loop will accelerate the demise of the entire ice sheet, drowning coastal cities. But that is not the worst of our troubles.
Other positive feedback loops include the melting of permafrost, the burning of the Amazon rainforest, and the release of methane hydrates from the ocean floor. The best science we have today tells us that once we cross the 1.5 degree Celsius mark, it becomes increasingly difficult to avoid tipping points that will generate at least 5 or 6 Celsius of total warming. That much warming would render much of our planet uninhabitable to humans, and turn much of the remainder into an unproductive wasteland.
Any environmental policy – no matter what the Party affiliation – that carries us across that key climate 1.5 degree Celsius boundary brings us to that tipping point. And remember the 30-year lag between the release of greenhouse gasses and their full impact. Scientists estimate the CO2 and other gasses already released in the last 30 years will add at least another 0.4 degree Celsius rise by 2045. Effectively, we have already created more than a 1.2 Celsius increase.
This approaches an environmental precipice; one we will plunge over, if we by continue Obama-style “slightly better” policies over the next decade. So a little better won't help. Only rapid and drastic reductions in the use of fossil fuels to dramatically decrease greenhouse gasses can prevent this. Read More