Lately there is a lot of talk about how the temperatures will be in 2017. It is also said that 2016 and 2014 have been the hottest since temperatures are recorded and that it is estimated that 2017 will also be very hot, although not the hottest.
Many people will wonder how meteorologists are able to predict these temperatures if they have not yet arrived. How do you know the temperatures that will be in 2017 if the year has just begun?
Very warm years
Since there are temperature records of the year 1880, the 16 years of this second millennium, they are the highest. Last year, it was the third year in a row that a new annual record in world temperature has been reached.
A controversy about weather forecasting arises from meteorology. Because, despite the abnormally high temperatures ever recorded, there is still skepticism against the anthropogenic origin of high temperatures and global warming. The root of this controversy arises from the inability of meteorologists to predict well the weather in three or four days. They take this as proof that scientists cannot predict Earth's climate within a few years or even decades.
If this is so, why are scientists confident that they can predict above-average temperatures months in advance, and how do climate predictions differ from weather forecasting?
The movements that the atmosphere has
Normally, to predict the weather several days in advance, the evolution of pressure patterns in atmospheric systems. Although the weather forecast two weeks in advance has improved enormously, because atmospheric systems do not persist for long, they become less accurate.
When it comes to predicting the formation of low pressure systems, it presents difficulties, since a movement of only about 75 kilometers to the east or west with respect to the predicted trajectory, can mean the difference between a blizzard, a windstorm and rain or a false alarm. Something similar happens with summer storms and rain predictions.
However, this does not mean that We should not rely on strong storm warnings and weather forecasts.
Weather predictions
Unlike forecasts based on meteorological systems, climate predictions for temperatures and precipitation use completely different data.
To predict these weather variables months, years, or decades in advance, they are based on the variations of the oceans, solar variations, volcanic eruptions and, of course, the increase in the concentration of greenhouse gases in the atmosphere. These variables evolve and change over the months and years unlike atmospheric systems that can change in a matter of hours or days.
An important factor that varies from a few months to a year is the phenomenon of El Niño. The periodic warming of ocean temperatures throughout the tropical Pacific. This pattern of ocean warming and its associated effects on the atmosphere exerts a strong influence beyond the tropics that can be factored into climate predictions.
Human and natural factors
In addition to the effects of the oceans and bodies of water, other natural factors such as volcanic eruptions are known to affect the rate of global warming. But it should be mentioned that, so far, the largest increase in global temperatures is due to the increase in the concentration of greenhouse gases (GHG) caused by humans and the industrial revolution.
Therefore, warming projections on broader time scales (multiple decades or more) are based on climate model simulations and our understanding of how sensitive the climate system is to future increases in atmospheric GHG concentrations. These models show that global warming in the not too distant future will be dominated by increased GHG levels compared to increases in natural temperatures or by ocean masses or volcanic eruptions.