Sat, Aug 08, 2015 - Page 9 News List

G7 embraces decarbonization in revolutionary breakthrough

By Jeffrey Sachs

This week’s G7 meeting at Schloss Elmau in the Bavarian Alps marked a major breakthrough in climate change policy. The seven largest high-income economies — the US, Japan, Germany, the UK, France, Italy and Canada — made the revolutionary decision to decarbonize their economies over the course of this century.

For the first time in history, the world’s major economies have agreed on the need to end their dependence on fossil fuels. US President Barack Obama, German Chancellor Angela Merkel and the other G7 leaders have risen to the occasion and deserve strong global approbation.

The historic breakthrough is recorded in the final G7 communique. First, the G7 countries underscored the importance of holding global warming to below 2°C. This means that the Earth’s average temperature should be kept within 2°C of the average temperature that prevailed before the start of the Industrial Revolution, roughly before 1800. Yet global warming to date is already around 0.9°C — nearly halfway to the upper limit.

Then, the G7 leaders did something unprecedented. They acknowledged that in order to hold global warming below the 2°C limit, the world’s economies must end their dependence on fossil fuels — coal, oil and natural gas.

Currently, about 80 percent of worldwide primary energy comes from fossil fuels, the combustion of which emits around 34 billion tons of carbon dioxide. This level of emissions, if continued in future decades, would push temperatures far above the 2°C upper limit. Indeed, with rising worldwide energy use, continued dependence on fossil fuels could raise global temperatures by 4°C to 6°C, leading to potentially catastrophic consequences for global food production, higher sea levels, mega-droughts, major floods, devastating heat waves and extreme storms.

The science is clearer than many politicians would like. For humanity to have a “likely” chance of staying below the 2°C threshold, a small reduction in carbon emissions is not enough. In fact, emissions have to fall to zero later this century to stop any further rise in the atmospheric concentration of carbon dioxide. Simply put, the world economy must be “decarbonized.”

The breakthrough at the G7 summit was that the seven governments recognized this, declaring that the 2°C limit requires “decarbonization of the global economy over the course of this century.” The G7 finally stated clearly what scientists have been urging for years: Humanity must not merely reduce, but must end, carbon emissions from fossil fuels this century.

Decarbonization is feasible, though by no means easy. It depends on taking three key steps.

First, we must become more energy efficient, for example, through modern building designs that reduce the needs for heating, cooling, and energy-intensive ventilation. Second, we must produce electricity with wind, solar, nuclear, hydroelectric, geothermal, and other non-carbon energy sources, or by capturing and storing the carbon dioxide produced by fossil fuels — a process known as carbon capture and storage (CCS). Third, we must switch from fossil fuels to electricity or hydrogen produced by zero-carbon electricity, or in some cases, such as aviation, to advanced biofuels.

The hard part is the practical, large-scale implementation of broad concepts in a way that does not disrupt our energy dependent world economy and does not cost a fortune to achieve. However, as the costs are tallied, it should be noted that runaway climate change would impose the greatest costs of all.

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