1.5°C looks like little on the thermometer: What does this number really mean for our planet?
How 1 degree warming already feels, we experienced last summer. 2018 may well go down in history as the year in which the effects of global warming for the first time became so evident around the entire globe: heat waves and floods in Japan, massive winter drought in Australia, the worst forest fires in California, unusual summer heat and drought in the entire northern hemisphere, the strongest monsoon in India for 50 years, with 51.2 degrees Celsius the highest temperature ever measured in Africa, extraordinarily strong tropical cyclones such as hurricanes "Michael" and "Florence". And all this at only one degree more! It is important to understand that at 1 degree warming, caused by us humans, we have reached the maximum temperature on Earth since the last Ice Age. It is no surprise that a planet with more heat becomes more turbulent and responds with more severe extreme events. With a global warming of 1.5 degrees we might be crossing a tipping point: Tropical Coral reefs may be permanently lost. Extreme weather events would become more likely. Sea levels would rise significantly. This is why every single tenth of a degree matters.
If we do not succeed in limiting global warming to 1.5°C, what are the consequences for us and our planet?
If we warm our planet by more than 1.5 degrees, we might approach other tipping points in the Earth system, which could lead to further self-reinforcing warming. For example, if the Arctic sea ice melts, this makes the polar region darker, where less solar radiation can be reflected. Or because thawing permafrost releases methane into the atmosphere and the soil turns from a store to a source of greenhouse gases. Or that carbon stored in trees get abruptly lost due to vast forest fires and dieback due to drought and disease. Unfortunately, we cannot rule out that a warming of 2 degrees may be a planetary scale threshold, which, if crossed, could tip the planet over to a point that inevitably pushes us towards a Hothouse Earth, where the climate would be self-warming due to release of greenhouse gases and heat from land and in oceans. Today we have only one decade left for an immediate CO2-turnaround to avoid major climate risks.
In the face of these dimensions: what can each individual do to make a difference? And what do you demand from companies and politicians?
We cannot load the full responsibility on individuals. To succeed in securing a manageable climate future for coming generations, we need large transformations of our societies, from becoming 100 % fossil-fuel free in only 30 years’ time, to shifting away from food production that destroys ecosystems. This can only be achieved through political leadership and responsible business behaviour. At the same time, we as individuals choose what we buy, how we move and what we eat. We as individual choose our leaders. So, no doubt, all individuals matter, as key parts of a global movement. Moreover, everyone can contribute a little, e.g. by reducing travel by car or plane, eating more fruits and vegetables and less meat and dairy products or by reducing food waste. Politics is influenced not only by its citizens but also by business. For ambitious climate politics, we need banks, insurance companies and big corporations just like the METRO to take responsibility. Sustainability must be framed as the more innovative, competitive and successful alternative. METRO could be at the forefront of this revolution towards a sustainable, climate-friendly industry. Because greenhouse gas emissions need to be halved in the next decade and then halved every further decade. By 2050, together we must bring CO2 emissions to zero.