This post is in response to Systemic Disorder commenter Palloy who thinks that peak oil will save mankind and that global warming “will not be as bad as +1.5°C.” I want to answer the question of what degree of warming we are already committed to if industrial civilization were to disappear off the face of the Earth right now.

Palloy is overlooking the part that aerosols from industrial activity play in temporarily cooling the planet. James Hansen called this the Faustian Bargain:

…Human activity modifies the impact of the greenhouse effect by the release of airborne particulate pollutants known as aerosols. These include black-carbon soot, organic carbon, sulphates, nitrates, as well as dust from smoke, manufacturing, wind storms, and other sources. Aerosols have a net cooling effect because they reduce the amount of sunlight that reaches the ground and they increase cloud cover. This is popularly known as “global dimming”, because the overall aerosol impact is to mask some of the warming effect of greenhouse gases.

Hansen’s new study estimates this aerosol “dimming” at 1.2 degrees (plus or minus 0.2°), much higher than previously figured. Aerosols are washed out of the atmosphere by rain on average every 10 days, so their cooling effect is only maintained because of continuing human pollution, the principal source of which is the burning of fossil fuels, which also cause a rise in carbon dioxide levels and global warming that lasts for many centuries…

The average global temperature rise thus far is about 0.85°C since the onset of the Industrial Revolution. Once industrial activity ceases and its accompanying aerosols fall out of the atmosphere, the average global temperature will jump to about 2°C, but it won’t simply stop there because Palloy forgets that there is a lag time involved with CO2 emissions. The effects we are feeling now were from our emissions 40 years ago:

…The estimate of 40 years for climate lag, the time between the cause (increased greenhouse gas emissions) and the effect (increased temperatures), has profound negative consequences for humanity. However, if governments can find the will to act, there are positive consequences as well.

With 40 years between cause and effect, it means that average temperatures of the last decade are a result of what we were thoughtlessly putting into the air in the 1960’s. It also means that the true impact of our emissions over the last decade will not be felt until the 2040’s. This thought should send a chill down your spine!…

This “committed warming” of past CO2 emissions whose effect will be manifested in the coming decades is about 0.6 degrees Celsius. Adding up the current warming of 0.85°C from the onset of the Industrial Revolution, the loss of aerosols with global dimming at 1.2°C, and the “committed” temperature rise from the 40-year lag time of CO2 emissions equal to 0.6°C, we get a total of 2.65°C. If all industrial activity stopped right now, we would already be committed to 2.65°C, a global average temperature rise of three times what we are currently experiencing. With all the drought, flooding, hurricanes, landslides, fires, and other manifestations of climate change that we are undergoing now, I shudder to think what the world will be like in 2050 and yet humans continue to burn coal and other fossil fuels at breakneck speed. According to the Climate Accountability Institute, half of all emissions have been produced in the past 25 years.

Now we get to the even more insidious aspects of anthropogenic climate change that very few comprehend. Dozens of self-reinforcing feedback loops have already been triggered, but we’ll discuss only one, the albedo effect, in the loss of our planet’s air conditioners, the Arctic and Antarctic:

(1)   An increase in temperature decreases the area covered by sea ice as it melts leaving a larger area of exposed ocean.
(2)   This decreases the reflection of sunlight as ice is far more reflective than the newly exposed ocean.
(3)   Reduced reflection increases the area’s absorption of heat from the sun.
(4)   This increases the temperature of the area, amplifying the original increase in temperature mentioned in (1).

A recent study calculated that the loss of Arctic ice reflectivity from 1979 to 2011 added an amplifying feedback to human warming equivalent to 25% of the heat captured by CO2 emissions during that same time.

We know that we don’t live in a linear world and that climate change is a non-linear phenomenon. Recent studies on abrupt climate change in Earth’s history reveal that temperatures have changed rapidly by 5°C in just 13 years. With the grand experiment mankind has irrevocably and haphazardly embarked on, the de-thawing of vast stores of permafrost and clathrates measured in the gigatons has commenced, creating the possibility for a sudden catastrophic release of such gases at any time. Methane, for about the first 10 to 20 years of its initial release before it breaks down into CO2, is many fold more potent as a greenhouse gas than carbon dioxide. Humans are too busy calculating everything in terms of economic profit with regards to newly exposed resources and shorter shipping routes in the Arctic to take the time to fathom what damage they have done. Industrial civilization has permanently disrupted the stable period known as the Holocene within which mankind and civilization have been allowed to prosper.

Thus, we can see that the world is changing quickly into an environment that may well be outside the habitability for humans. The timing of human near-term extinction is likely academic.

Apneaman left this message here just a short time ago:

Journalist Dahr Jamail & Professor Peter Wadhams say the resulting release of methane will lead to massive climate disruption, and that we have reached a point of no return.

Update (12-3-2014):

CO2 Takes Just 10 Years to Reach Planet’s Peak Heat (Not 40 Years)

In a study that could have important ramifications on estimating the impacts, costs and benefits of reducing carbon dioxide emissions, new research shows that CO2 brings peak heat within a decade of being emitted, with the effects then lingering 100 years or more into the future…

…The research, published Wednesday in Environmental Research Letters, provides policymakers and economists with a new perspective on how fast human carbon emissions heat the planet. Back-of-the-envelope estimates for how long it takes for a given puff of CO2 to crank up the heat have generally been from 40-50 years. But the new study shows that the timeframe for CO2 emissions to reach their maximum warming potential is likely closer to 10 years….
http://www.climatecentral.org/news/co2-emissions-peak-heat-18394