The study uses the MIT Integrated Global Systems Model, a computer simulation developed by the Joint Program on the Science and Policy of Global Change and supported by the US government.
It is the only model that interactively includes not only information about atmospheric, oceanic and biological systems, but also detailed treatment of possible changes in human activities - such as the degree of economic growth, with its associated energy use, in different countries.
The new projections suggest a median probability of surface warming of 5.2 degrees Celsius by 2100, with a 90% probability range of 3.5 to 7.4 degrees. This can be compared to a median projected increase in the 2003 study of just 2.4 degrees.
Amongst the 400 complex projections that take into account diverse scenarios, in particular those where there is no political action to reduce emissions, look much worse than before.
To illustrate the range of probabilities revealed by the 400 simulations, the team at MIT produced a "roulette wheel" (see this page) that reflects the latest relative odds of various levels of temperature rise. The wheel provides a very graphic representation of just how serious the potential climate impacts are.
The team explain that their computer models match the known conditions, processes and past history of the relevant human and natural systems, and the researchers are therefore dependent on the accuracy of this current knowledge. They warn that the odds indicated may actually understate the problem, because the model does not fully incorporate positive feedbacks that can occur, for example, if increased temperatures caused a large-scale melting of permafrost.
Study co-author Ronald Prinn, the co-director of the Joint Program and director of MIT's Center for Global Change Science, insisted: "The least-cost option to lower the risk is to start now and steadily transform the global energy system over the coming decades to low or zero greenhouse gas-emitting technologies."
Unfortunately, science does not drive global decision-making. The terrible drama of human society is that we are capable of producing scientists who can explain exactly what is happening, but not so far, the social and political structures – in a word, states – that will act on this information. Quite the reverse - as the body of evidence grows, state action to reduce emissions is actually declining.
That is because states do not stand even-handedly above society, doing the best for all. They represent the interests of one class – the capitalist class – and everything is made subservient to that – even at the risk of human and ecological catastrophe, as set out in the evidence published by the International Panel on Climate Change.
The only way to resolve this problem is for the governance of countries to undergo a democratic revolution, bringing into being new structures that serve the interests of the majority. Market expediency would no longer rule and scientific evidence could be taken seriously and acted upon.
Penny Cole
Environment editor
Image courtesy / MIT Joint Program on the Science and Policy of Global Change
No comments:
Post a Comment