The latest analysis of wind and climate data between 1978 and 2017 shows that the reduction in mean wind speeds observed up to 2010 has reversed, despite increased surface irregularities due to advancing urbanisation.
At the 2015 UN Climate Conference in Paris, 195 signatories concluded the Paris Agreement and committed to the goal of limiting "climate warming to significantly below two degrees" and to "undertaking efforts" to halt climate warming at 1.5 degrees.
When does Germany have to become CO2-neutral? Current studies show that the Intergovernmental Panel on Climate Change (IPCC) forecasts applied to determine the CO2 budgets of the individual countries are too optimistic. The latest evaluations take into account abrupt developments such as the already evident feedback effect on the climate, the melting of permafrost and the resulting release of additional greenhouse gases.
The sea level is rising in a non-linear way, i.e. ever more rapidly. In the entire last century, the sea level rose by around 16 centimetres. Currently the increase is some 3.6 centimetres per decade - more than double that! The cause of this acceleration can be seen in Greenland and the Antarctic, where the ice shields are melting at an increasing rate.
The village of Fairbourne in Wales will soon disappear. Already, banks are refusing to give its residents mortgages. The village is being abandoned in what the government calls a Coastal Risk Management Learning Project! It can no longer be protected from the impacts of climate change in the long term.
Extreme weather events are happening ever more often around the world. The duration and frequency of heatwaves already affect the security of food supplies. Climate change is dangerous! In California, more than a hundred thousand people are again fleeing from forest fires.
In Germany, the rise in temperatures is already much higher than the global average. The past decade was 1.9°C warmer. This comes with the threat of irreversible changes leading to a sudden tipping point with a drastic rise in sea level, mass species extinction and no prospect of recovery.
Net CO2 emissions need to be reduced to zero in order to stabilise temperatures at today's level. That means the volume of CO2 emitted into the atmosphere must match the quantity removed (e.g. through other actions). A balance between CO2 sources and sinks is termed net-zero emissions or climate neutrality, and is linked to a gradual decrease in the CO2 concentration in the atmosphere. The aim is to achieve an equilibrium where emissions are captured by the biospheres on land and in the oceans, combined with an almost constant global temperature.
The fluctuation in air pressure differences between the Azores High and the Icelandic Low is known as the North Atlantic Oscillation (NOA). The latest findings of scientists working under Zhenzhong Zeng at Princeton University show that the NOA is the main cause of the most recent, rapid reversal of the reduction of wind speed up to 2010. Since then, the average wind speed has been rising again, at a rate of 0.25 m/s per decade.
However, it will only be possible to limit global warming to 1.5°C or 2°C with human intervention in many relevant areas which must succeed in cutting CO2 by the necessary amount. Emissions must decline very rapidly in all major sectors of society, including construction and housing, industry, transport, agriculture, forestry and other land use (AFOLU). Apart from ending power generation from coal, the measures necessary to reduce greenhouse gas emissions are the electrification of transport, reducing our CO2 footprint in food consumption and increasing the use of renewable energies.
Together, we can fight against the dramatic developments that have recently been in the spotlight again. If we assume a fictional 2.5-MW wind turbine with a diameter of 120 m, together with the wind speed increase proven by Princeton University, the energy yield in Europe could have been higher between 2010 and 2017 by 22 +/- 4%.
But there is still no strategy for repowering existing projects or for limited subsidisation of older plants over a transition period. Such a programme would cushion the effects of the coronavirus crisis on share prices. It would also bridge the gap until the enforcement of the CO2 price rise to up to EUR 55 per ton by 2025, which the German government has already resolved.
According to Heike Kröger and Ubbo de Witt, Managing Partners of the Projekt Group, "It's not enough for the government to merely announce policies. It must also create the correct framework conditions based on a progressive vision. If this happens, we believe the world press doesn't have to be dominated by bad news, and renewable energy generation can make an effective contribution to climate protection." In 2019, the average wind energy yield was around 3.3 MW, which was more than experts had predicted.
This unexpected success shows that we can (still) take action so that the negative scenarios elsewhere don't turn into bitter reality for us as well!