In 2015, the Paris Agreement was the first climate change treaty directly aimed at limiting the rise of global temperatures to between 1.5°C and 2°C (above pre-industrial levels). Ever since then, climate action has focused on setting an inter-governmental blueprint to address the agreement’s pledges. But a question looms: can employing the green energy technologies we have at hand today provide a definite solution for climate change mitigation?
Most discussions concerning the mitigation of climate change revolve around inter-governmental intervention, while regularly veering their focus away from technologies that could warrant a switch in the production and use of green energy. Both are fundamentally correlated areas of the debate. But the latter ideally proposes a systematic method to evaluate how likely it will be that commitments, set so over-enthusiastically at policymakers’ tables, are abided by. So, next time, instead of waking up to a headline that reads “Supply and demand of coal, oil, and gas must be phased out by 95%, 60%, and 45% by 2050”, we must know what technologies could guarantee the adherence to inter-governmental pledges directed at climate change action.
The above mock-up headline is nothing else than the main takeaway from April’s latest IPCC report. The same report states that fossil fuel emissions must peak by 2025 if we are to keep within 1.5°C of global warming set at the 2015 Paris Climate Summit. This assessment, published by the Intergovernmental Panel on Climate Change, written, and curated by hundreds of leading scientists, is the latest cry out for the restriction of greenhouse gases emissions. Nonetheless, the notion that releasing man-made carbon dioxide into the atmosphere would affect global temperatures has been common scientific knowledge for centuries. In 1896, Svante Arrhenius first accurately quantified the rise in global temperatures due to the release of CO2. In the past century, the IPCC itself was founded, in 1988, with the aim of assessing the science related to climate change, and in 1992 the UN held its first Framework Convention on Climate Change. Regardless, carbon dioxide emissions have risen. More recently, the 2015 Paris Agreement established the first specific national commitments aimed at diminishing future greenhouse gases emissions, but will such be a feasible feat with the technologies we have at hand today?
Energy use in industry, inside buildings and in transport accounts for nearly three quarters of annual greenhouse gases emissions. And, as expected, fossil fuels power 82% of the global energy supply. More notably in 1992, at the time of the first UN convention on climate change, this value was 86%. In thirty years, mobilizing reductions of greenhouse gases’ emissions has resulted in a meagre 4% decrease of fossil fuels’ usage. This is the reason why technology development strikes at the heart of climate change response. Once regulatory and bureaucratic paths are set, springing from governmental commitments to reduce emissions, new technologies become the guiding lights for our course of action. They are the tangible weapons in our fight against climate change.
Indeed, we are all painfully aware that the oversimplistic prospect of halting the use of coal, oil, and gas overnight—while an enticing idea—is simply not a viable option. However, like any global transition, the decarbonization of the global energy supply will be a gradual process. Photovoltaic cells, taking their shape in technologies like solar panels, have rightly become the emblem of renewable energy production. Today, photovoltaic cells stretch their ability to transform sunlight into electricity from the four tiny PV cells charging our solar-powered calculators to vast ‘solar fields’ in the desert. Better yet, the power density of photovoltaic cells is higher than that of any other form of renewable energy. The annual average power reached by PV cells in sunny weather is more than a magnitude higher than what biofuels can achieve. And yet, the make-or-break moment for PV cells, which happened in 1958 on a satellite orbiting earth, defines their fundamental downfall to this day: they are an expensive piece of technology. They could first be employed in space because money was no object during the golden years of space exploration, but it took a long time for production and installation prices to sink enough in order for their technology to be made readily, commercially available. With high probabilities, as long as their prices continue to decline we will see more and more solar panels sprouting on our cities’ roofs.
Wind power is the other insignia of renewable electricity generation. And yet, the machines making wind power extraction possible are standing monoliths to fossil fuels. Manufacturing one 5-megawatt turbine averages 800 tons of steel. If by 2030 wind turbines are to meet 25% of global energy demand, the fossil fuels necessary in order to manufacture the required steel would be the equivalent of 600 million tons of coal. Nevertheless, in one year of its two-decade life span a wind turbine could generate the electricity it took to produce it. And yet, until the entire energy demand needed to commercially produce wind turbines and photovoltaics is itself supplied by renewable energy, the taint of fossil fuels will linger onto the emblems of green energy production.
Conversely, there are some cases where it is clear that the machinery necessary to facilitate the green energy transition simply doesn’t yet exist. An example of this is the electric container ship. So far almost all container ships, trucks, and freight trains are fuel-powered. Hence, in the intrinsically globalized world in which we live today most traded goods are transported by fossil fuels. In particular, diesel, due to the efficiency of its combustion, is the uncontested fuel of long-distance travel. But why can an electric-powered container ship not prevail in long-distance maritime travel? Yara Birkeland, the first autonomous and entirely electric container ship, departed for its maiden voyage in 2021. Even so, the ship, travels distances only as far as 56 km between Herøya and Larvik, in Norway. Instead, nowadays diesel-powered ships travel 400 times longer distances, can carry 200 times more cargo, and operate at 3 to 4 times greater speeds. Then, substituting cargo ships for electric ones today is simply a disappointingly unrealistic prospect that would heavily impair global trade networks. Until electric container ships become efficient substitutes of diesel-powered ones, there will be no major global shifts in the transport of goods over long distances. And our only solution to the lack of more efficient technology remains just one: time.
Two things emerge clearly: we are exceedingly reliant on the technologies that only future innovations could bring. And, that because of this, investment in the development of such technologies remains crucial. If the decarbonization of our energy supply is achieved, the context and economy in which new energy sources will operate will be an entirely different one. Intermittent renewable energy, generated by wind turbines and photovoltaics, is generally a less controllable energy source; we simply cannot determine when the sun will shine, hence the supply of energy will always be conditional to weather as much as to human intervention. Whether we are looking forward to the invention of new carbon-removal technologies or that of pollution-free vehicles, the green energy transition will undoubtedly continue to be a slow one (while the background clock ticks).