Today is the third of my “Prediction Saturday’s”. The intent of my “Prediction Saturday” posts are to put forward a prediction about the near future, e.g. 15 – 20 years from now.
Last week I made a bold and optimistic prediction regarding the future of energy. The prediction was that in 20 years’ time, alternate energy technologies that exploit the (practically) infinite power of the Sun (e.g. 3D printed and/or highly efficient solar panels; biofuel producing algae) would be sufficiently advanced to provide virtually free energy to individual households. Each household would be energy self-sufficient and demand for oil would plummet.
Today’s prediction is unfortunately a gloomy one. I predict that there will be one (or more) climate shocks that will likely accelerate the warming of the planet beyond what is already anticipated. Related to this would be a dramatic loss of biodiversity in the oceans due to the acidifying of oceans, coral bleaching and overfishing.
The Skeptical Science website looks at both sides of the argument of “How reliable are climate models?” The website explains that “models are tested against the past, against what we know happened. If a model can correctly predict trends from a starting point somewhere in the past, we could expect it to predict with reasonable certainty what might happen in the future. Where models have been running for sufficient time, they have also been proved to make accurate predictions. The climate models, far from being melodramatic, may be conservative in the predictions they produce.” For example, here’s a graph of sea level rise:
“Here, the models have understated the problem. In reality, observed sea level is tracking at the upper range of the model projections. There are other examples of models being too conservative, rather than alarmist as some portray them. All models have limits – uncertainties – for they are modelling complex systems. However, all models improve over time, and with increasing sources of real-world information such as satellites, the output of climate models can be constantly refined to increase their power and usefulness.”
To summarise, models are good at predicting trends as long as the trends are evidenced in the data from the past.
According to the models, global warming can be explained by increased CO2 in the atmosphere. Recognising that global warming is a global catastrophic risk, the countries of the world have been meeting for the better part of two decades to agree on emission cuts. Finally, at the Paris climate conference in Q4 2015, 195 countries adopted the first-ever universal, legally binding global climate deal. A long-term goal of keeping the increase in global average temperature to below 2°C above pre-industrial levels was agreed.
However, the scale of the agreed emissions cuts – while deeper than before, but still not deep enough – suggests that global temperatures will rise above 2°C. The following graph suggests that even with the agreed emissions cuts, the gigatons of CO2 in the atmosphere will continue to grow albeit at a slower pace.
The agreed emission cuts were calculated to limit global temperature rise to 2 degrees or less based on the current models of climate change. Remember, the climate change models work well at predicting trends based on historical data. But what if there was another variable that is not captured in historical data, that could dramatically impact global temperatures,?
I am specifically referring to the release of methane from the permafrost that covers 24 percent of the northern hemisphere land (and some of the southern hemisphere) and from methane hydrates in the Arctic Shelf.
Permafrost and Methane Hydrates
Permafrost stores an immense amount of carbon and methane (twice as much carbon as contained in the atmosphere). Methane hydrates can be thought of as methane gas frozen into ice structures. They’re formed at cold temperatures and under high pressure—conditions that are both present beneath layers of frozen permafrost. The amount of methane hydrates in permafrost could range anywhere from 7.5 to 400 billion tons of carbon-equivalent. Methane hydrates are also abundantly present in and near the Siberian Ice Complex, or Arctic Shelf, which provides a shelf-like structure to support the land and coastline on top of it.
Over the last few years as global temperatures have reached record levels, there have been worrying signs that the methane stored in permafrost and ocean bed methane hydrate stores is being released into the atmosphere and at increasing rates.
Recently, a loud explosion in Siberia that was heard by villages 70-100 km away was attributed to a methane explosion as the methane hydrates under the permafrost thawed and released their methane. Craters caused by methane explosions have been turning up in Siberia since 2013. You can even watch on people fooling around burning the methane escaping from under the ice on YouTube: https://www.youtube.com/watch?v=FM0hczFNDZI
Beyond a certain temperature increase, a dangerous feedback loop may come into play: increasing temperatures cause more methane to be released into the atmosphere which in turn causes increasing temperatures.
Oh, I should have mentioned that Methane is a greenhouse gas that has 20 to 25 times more warming power than carbon dioxide. Each kilogram of Methane that enters the atmosphere is equivalent to 20 to 25 kilograms of CO2 in terms of its global warming impact.
Now the scary part: the amount of carbon sequestered in permafrost is four times the carbon that has been released into the atmosphere due to human activities in modern time; and, a sizeable amount is in the form of a molecule that has 25 times more warming power than CO2! Not encouraging is it?
The Paleocene-Eocene Thermal Maximum (PETM)
The previous extreme global warm-up happened 56 million years ago, when Pangaea was splitting into separate continents. It is suspected that huge amounts of carbon were released into the atmosphere and oceans in the form of carbon dioxide and methane. The globe warmed 5 to 9°C. Most ecosystems were able to adapt because the warming took place over thousands of years. Today, global temperature could be warming at a rate that is too fast for ecosystems to adapt.
The PETM warmth lasted 200,000 years before the Earth system was able to remove the extra CO2 from the atmosphere.
Our planet is/was in natural equilibrium when it came to global temperatures (sure, temperatures do shift naturally due to causes such as Milankovitch cycles—variations in the Earth’s orbit that change its distance from the Sun, which spur ice ages and subsequent warming). Now it seems the equilibrium has been disturbed by manmade activity. The scary thing is, as the permafrost melts and releases methane into the atmosphere, it is impossible to say how much the Earth will warm over the next few decades let alone fifty to a hundred years. The signs are that our current models are too conservative and have not sufficiently accounted for the effect of methane and the possibility of reaching a tipping point / feedback loop situation.
It is almost certain that the current emissions cuts will not keep global temperatures below a 2 degree increase. And these cuts did not account for increased methane in the atmosphere released by thawing permafrost. We have a very short window to try to restore equilibrium. Beyond extreme cuts and adoption of alternative energy sources we may need to try some radical solutions to scrub excess CO2 from the atmosphere. While such solutions are bound to be expensive, a global temperature increase of more than 2 degrees would be devastating. An increase of 5 degrees, similar to the PETM, would be truly catastrophic. Consequences of global warming include: sea level rise, drought, famine, increased weather intensity, ocean acidification, coral bleaching, food disruptions, mass migrations, etc.
Here are additional sources if you would like to dig deeper into this interesting (and pertinent!) topic: