Debate

How climate change came about

Our planet Earth was formed about 4.5 billion years ago; life has existed on Earth for about 3.7 billion years and homo sapiens began a remarkable evolution about 300,000 years ago. From the beginning, the Earth has been in a constant evolution, and this is especially true for the climate on our planet. There have been eras without any ice at all, and at one point the Earth was entirely covered in ice and snow.

Nevertheless, what we are currently experiencing with our climate is new: Why?

Since at least the early 1970s, we have no longer been able to explain climate dynamics - especially the development of CO2 concentration in the atmosphere – through only natural causes. At that point (at the latest) humans became a geofactor. Immense human population dynamics - which can be seen in our currently eight and soon ten-billion-person world population - and the intensive, large-scale land and fossil fuels use have led to a drastic development of greenhouse gas emissions, especially CO2. This process is causing increased global warming.

Political objectives in the fight against climate change

Since the Kyoto Protocol negotiations in 1995, reinforced by the 2015 Paris Agreement to meet the 1.5°C target, we know that action is acutely needed. We must reduce man-made greenhouse gas emissions. As a result of increased social awareness, the EU has agreed to climate neutrality with the European Green Deal and cooperation with many other countries. Germany and other EU countries want to achieve climate neutrality not in 2050 but in 2045. This goal can only be achieved if we phase out the greenhouse gas-emitting use of fossil fuels. This means a dramatic change in our energy supply systems, not only for important industrial production processes in the chemical, cement, steel, glass, and fertilizer industries, but also in the mobility and housing sectors. In these two sectors, the focus is on heat and in land use. To this end, a further massive expansion of CO2-free renewable energies is planned throughout the EU. In Germany, this currently accounts for around 17 percent of energy supply, with over 50 percent of this coming from biomass – particularly from the use of wood. Across all sectors of energy supply, wind and solar power currently provide about 7-8 percent of our energy supply.

The energy transition: Progress and barriers

Although the expansion of renewables has not progressed very quickly in recent years, in 2021 Germany added 484 new wind turbines and had more photovoltaic installations than ever before. Despite this, the share of renewables in the electricity sector was around 42 percent, well below the noteworthy 46 percent of the previous year (2020). The reason for this was a significantly lower wind returns. Because of this lower wind energy yield and, as a consequence of increased coal use, CO2 emissions in Germany rose by around 4.5 percent in 2021 compared with the previous year.

As for the actual consumption of electrical power in Germany, it is about 80,000 megawatts (MW) for a typical weekday and about 40,000 to a maximum of 60,000 MW on a weekend day. Currently, the electrical output of conventional power plants in Germany is about 110,000 MW. With this (still) available capacity, we could cover our electricity needs including "downtime" for maintenance and repair work on the corresponding infrastructures.

With the planned termination of high-emission coal-fired power plants and after the already completed shutdown of all nuclear power plants, lower-emission gas-fired power plants are to be built to secure the necessary base load. These can also be operated with hydrogen in the future. At the same time, some of the conventional power plants that would then be formally shut down would have to be transferred to the so-called grid reserve in order to be reactivated to supply electricity for certain demand situations, such as dark lulls, i.e. for times without sunshine and wind. If, at the same time, we assume greater electrification, for example for e-mobility, or in the household sector through heat pumps, or for the chemical industry, then the demand for electricity will again increase significantly. And to meet this demand, the expansion of renewable energies would have to be significantly increased once again. This will also increase the already existing need for new transmission and distribution networks.

One effect of climate change is different weather. Or to reformulate this concept: without different weather, there would be no climate change. This may sound banal, but it is highly relevant to our debate, because different weather means different wind regimes. The idea that we will build more new wind turbines and then harvest more wind energy is - at least in linear terms - not correct. It can be more, but it can also be less, as we experienced in 2021 compared to 2020. Other weather also affects solar energy, for example through changes in cloud cover, or through or changes in bioenergy resulting from fluctuating biomass production caused by droughts, floods, or pest infestations.

Hydrogen - energy carrier of the future

Even though the electricity sector is increasing in importance due to increased electrification in various areas, the other two sectors of our energy supply, namely heating (including refrigeration) and mobility, which together account for more than 75 percent of our energy supply, are currently the subject of intensive discussion; this is because fossil fuels - in addition to coal, natural gas and crude oil, which account for up to 90 percent of consumption - continue to play the central role in these areas. It is therefore necessary to replace these fossil energy sources with a new climate-neutral energy carrier. This will certainly be hydrogen. It the key energy carrier of the future. This is because the legislative milestones for achieving climate neutrality in the EU can only be realized if fossil fuels are replaced by a climate-neutral energy carrier. For this reason alone, climate-neutral hydrogen is not just one possible solution, but the central one for establishing the most comprehensive climate protection possible. The question is, when will hydrogen--and we are talking about demonstrably climate-neutral hydrogen--be available in sufficient quantities? And at an appropriate cost?

From the very beginning, the EU's hydrogen strategy has been geared toward using "green hydrogen" - that is, climate-neutral hydrogen produced from water using wind power and solar energy via electrolysis. This project also makes it possible to use the sporadically occurring electricity surpluses for the production of hydrogen, i.e. electricity from wind and sun that cannot be used as of now but is nevertheless financially supported. It should also be considered that climate-neutral hydrogen can be produced not only with renewable energies via the electrolysis process, but also in other ways. Keywords here are blue, turquoise, or even red hydrogen. The EU will also be dependent on imports for the use of hydrogen. In Germany, the import share could be around 70 percent of the demand. Imports of green or climate-neutral hydrogen or corresponding hydrogen derivatives make sense above all if the domestic energy demand in the exporting countries is realized as climate-neutrally as possible. Exporting green energy while continuing to use fossil fuels in the exporting country is not a realistic solution for climate protection, because climate change is a global problem.

Right as it may be to focus on electrification and direct hydrogen use (for example, for steel, cement, and fertilizer production, for fuel cells or also in the area of heat), it is imperative to use hydrogen for existing infrastructures, especially for existing technologies in the transportation sector. Despite the debate in the EU to ban internal combustion engines in new car registrations from 2035, the true problem is not internal combustion engines but climate-damaging fossil fuels. This issue applies equally to aviation, shipping, and heavy goods traffic. Additionally, only openness to technology will keep the EU in a leading role in the hydrogen economy in international competition. This requires the immediate implementation of a broad-based research and application, as well as an understanding that the whole endeavor is a learning process in which setbacks are a gain in knowledge. In this framework, there is no contradiction between synthetic fuels and e-mobility - whether in the air, on water, or for all land-based transport. After all, climate protection is not only about avoiding future CO2 emissions through new infrastructure to be built, including new transportation technologies, but also about making any possible CO2 savings today. It is therefore also important to bear in mind that we need a well-founded framework that consistently makes our CO2 footprint a central priority - even if this is difficult at one point or another and associated with certain uncertainties. That, too, is then a constructive learning process.