Kassel. Professor Hans-Joachim Schellnhuber, Director of the Potsdam Institute for Climate Impact Research (PIK), which he founded in 1992, is one of the world’s foremost experts in his field. In an interview with WINGAS, he provides insight into what has happened since the Paris Climate Agreement – and what hasn’t.
Professor Schellnhuber, the United States has withdrawn from the Paris Climate Agreement and is again opting for CO2-intensive energies such as coal and oil. How serious are these developments and what is your forecast regarding international efforts to protect the climate?
America is indeed relying on gas from fracking. That’s cheaper, but at the same time only half as damaging to the climate as coal. However, in particular states like the high-tech region California – which on its own would be the world’s sixth-largest economy – are pursuing an ambitious climate policy. That mitigates the destructive influence from Washington to a great extent. And that’s also the international perception.
It was agreed in Paris in 2015 to limit the increase in temperature to two degrees above pre-industrial levels. How can decarbonization of the global economy succeed?
Together with colleagues, I have presented a road map for that in “Science”, probably the most important scientific journal there is. We demonstrate in it how halving emissions every ten years will result in zero net emissions by 2050. We have also itemized concrete measures: from phasing out coal to electromobility, from solar power to urban construction using wood and carbon fiber instead of steel and cement. The technologies are there – we just have to scale them up.
Germany aims to reduce its CO2 emissions by 80 percent by 2050. What role will conventional energies still play then?
If we cut emissions by 80 percent, then fossil fuels are almost completely out of the equation. We’ll then still have residual emissions from some industrial processes and especially agriculture, and they are certainly a challenge. But Germany is currently definitely not on track to actually reduce its greenhouse gas emissions by four-fifths by 2050. Without additional measures, we’ll fail to achieve our climate targets. And another aspect must be considered: We actually need to cut our CO2 emissions by 100 percent by the middle of the century, which means more sharply than pledged.
What role does natural gas as a fuel play in international climate protection?
Gas can certainly be helpful for a transitional period, since it’s only half as dirty as coal. And gas-fired power plants can be put on stream faster if there are fluctuations in the electricity fed in from renewable sources when there’s no wind or sun. However, nuclear power and coal stations are designed as base load power plants, which doesn’t match the world of renewables. Yet it’s very obvious that gas also has to be eliminated from the system within a few decades. It’s an open question as to how far it’s then possible to use new forms of gas, such as hydrogen that is produced by solar power and reacts with CO2 to form methane. But companies in the gas industry should address that question very quickly if they want to survive.
What does Germany have to do to achieve its ambitious climate targets?
The first step is to phase out coal – and that has to start with lignite. It’s incredible that a high-tech country such as ours still holds records when it comes to what is the dirtiest of all fossil fuels. To ensure an orderly transition, we need a phase out commission that also identifies alternative economic perspectives, such as in the field of electricity storage technologies, for the affected regions, like Lausitz in our state of Brandenburg. We also need to change the direction in the financial sector and create general conditions so that investments are withdrawn from fossil fuel industries and channeled into clean innovations. In the mobility sector, we have to achieve electrification and the broad use of hydrogen. And so on, step by step. It is essential that we actually start down that road now.