Even though clean energy technologies have experienced substantial rapid growth in recent years, their combined efforts were not enough to prevent the largest single-year increase of atmospheric CO2 release since 1984. In 2013 alone, the atmospheric CO2 concentration jumped by 2.9 parts per million (ppm) to a total of 396 ppm. A consortium of scientists of the World Meteorological Organization (WMO) believes that the sharp recent increase in atmospheric CO2 is partly due to a depletion of major carbon sinks, such forests and oceans, that have taken up CO2 in the past, which has previously prevented the gas from going into the atmosphere. Atmospheric CO2 levels are now 142% of pre-industrial values with the symbolic 400 ppm milestone only being 1-2 years away. To make matters worse, the concentration of other potent greenhouse gases have also risen from their pre-industrial values, including methane (253% of pre-industrial value) and nitrous oxide (121% pre-industrial value). From 1990 to 2013, increases of atmospheric greenhouse gases has caused an overall increase of 34% of radiative forcing, the main mechanism of the global warming effect. This is already causing significant changes in the global climate.
[caption id="" align="alignnone" width="542"] CO2 Sources and Sinks - Source: CO2Now.org[/caption]
The figure above outlines the major sources and sinks of atmospheric CO2. The largest emitter of atmospheric CO2, by far, are cement production and the burning of fossil fuels. The largest cause for fossil fuel burning is energy generation, whose infrastructure still relies heavily on coal, oil and gas which combined provide ~80% of the global energy supply.
[caption id="attachment_8258" align="alignnone" width="494"] Global Energy Suppliers - Source: PBL Netherlands[/caption]
As seen from the graphic above, even though the share of some fossil fuels, such as oil and wood fuel, have been decreasing, the total amount of exajoules generated using those sources has been increasing globally. Renewable energy technologies, including hydropower nuclear, only represent a minimal share in the world's energy supply. The growth pattern of solar, wind and biofuels shows promise for the future, but the technologies have to make significant capacity increases to offset the increasing global carbon emission.
The good news is that global economies are decarbonising at 1.2%/year on a per dollar of GDP basis, the bad news is that this decarbonisation rate is not fast enough. At this current rate, the overall global warming during the 21st century would amount to 4C, which would have severe consequences for the global climate and and global sea level rise. According to a recent report by PwC, decarbonisation has to be accelerated by more than 5x of current levels, to a rate of 6.2%/year per dollar GDP, to reach the scientifically desired target of 2C warming, which would avoid the worst consequences of climate change. PwC decarbonisation units couple economic growth with CO2 emissions. This provides a good basis for discussing given that economic growth arguments are often introduced in emission policy debates.
[caption id="attachment_8259" align="alignnone" width="510"] Decarbonisation Scenarios Calculated by PwC - Source: PwC[/caption]
The largest emitters of CO2 remain the China, the United States and the European Union. The United States has recently benefitted some a natural gas boom, which has helped decrease its CO2 emission, but the US has still increased emissions on a carbon intensity basis (CO2 emitted per dollar GDP). Even though China's CO2 emissions have been increasing, the country has been decarbonising at 4.1% when measured in carbon intensity. The results for the different countries in the European Union are mixed, even though the entire EU decarbonising at 2.5% when measured in carbon intensity. The country with the largest decarbonisation was Australia with 7.2%. This was also the first year that the E7, the 7 emerging economies, beat the G7 in decarbonisation. The economies decarbonised at 1.7% and 0.2% respectively.
[caption id="attachment_8260" align="alignnone" width="539"] Carbon Emissions From Different Countries - Source: PBL Netherlands[/caption]
As alluded to previously, it is difficult to have a debate about reducing carbon emission without introducing arguments of economic growth. In the past, reducing carbon emission and enhancing economic growth have been viewed as opposing forces, but a new study by the Global Commission on the Economy and Climate Change indicates that does not have to be the case. The study found that ambitious measures to limit emissions would only cost ~5% percent more than the amount of capital predicted to be spent on the construction of new infrastructure using established practices. The cost of introducing cleaner energy technologies would then be offset by secondary benefits of clean tech, such as enhanced public health due to less air pollution and lower fuel costs for transportation and energy generation. Moreover, introducing clean energy technologies would also catalyze economic growth in new types of markets that would arise from the modernized energy infrastructure.
The cost of renewable energy technologies has also been plummeting so fast in recent years that clean energy systems have emerged as increasingly economically viable energy sources for large-scale application. In order to benefit from the economic potential of clean energy technologies, however, the current policy environment needs to change. Current policies and economic subsidies still favor fossil fuels significantly, which can be seen from the fact that the annual $600 billion global subsidies spent on fossil fuels amount to more than 6x of the global annual subsidies spent on renewable energies. Lowering fossil fuel subsidies will be difficult given the high reliance of the current energy infrastructure on fossil fuels, as well the substantial amount of private interest invested in them.
The releases of the aforementioned reports and their associated data come at a critical time, as world leaders will gather next week in New York City to discuss climate change. Moreover, a new global climate agreement is expected to be signed in Paris in December 2015, which will then take effect by 2020. The results of the discussions in New York City and the details of the Paris 2015 climate agreement will greatly influence the future of the global energy infrastructure and the associated carbon emissions.
Ever increasing carbon emission clearly indicate humanity's reliance on fossil fuels in our carbon based economies. It is clear that carbon based fuels are currently dominating the energy game, but some recent trends indicate that clean energy technologies have the potential to make a huge comeback if given the opportunity.