Much of the globe has been plagued by high temperatures in recent months, and 2018 is likely to be one of the warmest years in modern times.
But this may just be the beginning. According to a new study, the next five years will also be abnormally warm on Earth.
The study, published in Nature Communications, was conducted by researchers operating in France, the United Kingdom and the Netherlands.
The results suggest that the period 2018-2022 will be warmer than expected, with an increased likelihood of extreme temperatures during some periods.
The study is based on a statistical method that takes into account that the climate is fundamentally a chaotic system.
The intention has been to capture the natural, internal variation in weather systems, which is often very difficult to predict – unlike the changes that are due to external events, primarily human emissions of greenhouse gases and volcanic eruptions.
It is the natural variation that is dominant in the short term, which determines temperatures and precipitation on an annual basis – and which can sometimes seem to run counter to the long-term trend.
According to the researchers, the method worked well when they tested it on the climate changes that have already taken place in recent decades, so they believe the forecast for the next five years is close to the truth.
It suggests that the temperature increase on land could be a few hundredths of a degree by 2022. For example, for 2018 the forecast is an increase of 0.02 degrees, for 2018-2019 0.03 degrees. This may sound marginal, but then one should consider that this is an extra increase, in addition to the expected one.
”"That's what's added due to the natural variation in the oceans and atmosphere. This means that the warming overall will be stronger than expected," says Heiner Körnich at SMHI's research department.
On average, the temperature on Earth has increased by 0.05 degrees every five years over the past 100 years.
”An increase of 0.02 degrees in that perspective is quite a lot,” says Körnich.
He thinks the researchers' method seems reasonable.
”This is the first time it has been used to derive a global average temperature,” he says.
At the same time, he points out that there is a broad uncertainty in the results – and the study says nothing about what will happen in individual places on Earth, such as Northern Europe.
”"The regional variations could be much greater. The uncertainty means that it could also be colder, but most likely it will be warmer. But we will get the results quite soon. In five years we will know if the forecast was correct," he says.
Source: TT
