The Scale of the Global Climate and Energy Challenge

DEVON SWEZEY
Staff Blogger
Second-year MA Candidate at SAIS Washington

Over the next half century, the world will face twin challenges: first, rapidly expanding the global energy supply to meet increasing demand, and second, simultaneously decarbonizing the global energy supply to stabilize the climate. While some progress has been made in developing and deploying zero-carbon energy technologies to meet these two challenges concurrently, the rate of clean energy adoption has been far too low relative to overall energy demand. Indeed, for the last two decades there has been a nominal expansion of the share of carbon-free energy sources in the global mix.

The scale of the global climate and energy challenge is unforgiving. Global energy demand has nearly doubled since 1980 and is set to double again by 2050, according to the International Energy Agency. Moreover, virtually all of the increase in energy demand is predicted to come from developing countries, which will use ever more energy inputs to sustain their rapid economic growth. At the same time, limiting the long-term global mean temperature rise to 2.0 to 2.4 degrees Celsius—the official target endorsed by the U.N Framework Convention on Climate Change—would require a 50% reduction in CO2 emissions below 1990 levels. In other words, global carbon emissions would have to fall from 35.6 Gt (the 2012 level of global emissions) to less than 11 Gt per year by the year 2050, and continue declining thereafter.

What does this mean in terms of energy supply? Let’s look at the numbers. First, the world would need to eliminate all coal and natural gas consumption and replace it with zero-carbon energy sources. In 2010, Electricity generation from fossil fuels totaled 14,446 terawatt hours (TWh), according to the International Energy Agency (IEA World Energy Outlook 2012, page 182). Replacing that electricity with nuclear power stations, for example, would require the construction of 2,065 new 1 gigawatt hours (GW) nuclear power plants (assuming a capacity factor of 80%). But given that electricity generation accounts for about 40% of all global CO2 emissions (IEA WEO 2012, page 263), this would not be enough to reach the climate target. Thus transportation, which accounts for 23% of global carbon emissions, would also need to be decarbonized, perhaps by using electric vehicles. This would necessitate hundreds of GW of new nuclear power stations.

Yet this still does not take into account the expected growth in energy demand from now until 2050. Assuming that world electricity demand grows by 2% per year from 2010 (18,443 TWh) until 2050, the world would need 22,280 additional TWh of zero-carbon electricity, or the equivalent of an additional 3,180 nuclear power stations. Thus decarbonizing the electricity supply, which is only one component of the overall energy supply, would require the construction of 5,245 nuclear power plants, or about one new nuclear power plant every three days from now until 2050. If we were to include future consumption by the 1.5 billion people around the world who currently lack any access, the number would be larger still.

A similar analysis could be done using wind turbines—the world would need to construct 2.8 million 5 megawatt (MW) wind turbines from now until 2050, assuming 30% efficiency—or solar. The global solar photovoltaic (PV) industry reached a significant milestone in its 50-year history when cumulative global-installed solar PV reached 100 GW earlier this year. Yet to decarbonize the global electricity supply, the world would have to deploy 100 GW of PV panels every 66 days from now until 2050. Any way you cut it, the scale of the challenge is massive.

So how is the world doing in its quest to decarbonize the global energy supply? Not so well. Even though renewable energy technologies, such as wind and solar PV, have been growing rapidly, progress in decarbonizing the global energy supply has stalled. According to the BP Statistical Review of 2013, the share of carbon-free energy in world energy consumption stood at 13%, essentially the same as its level in 1995.

It is certainly true that renewable energy technologies have started to expand in the electricity sector and are expected to continue to grow quickly in the coming decades. The IEA estimates that the share of renewable energy generation in the global electricity sector is expected to rise from 20% in 2011 to 25% in 2018, with the share of non-hydro renewables increasing from 4% to 8%.

Yet clean energy continues to be outpaced by the growth in fossil fuels. Current rates of clean energy deployment are not sufficient to meet the international community’s target for climate stabilization. To achieve these goals, a much larger international effort must be pursued to research, develop and demonstrate new clean energy technologies and accelerate their introduction into the marketplace—the topic of a future post.