Just half a degree Celsius increase was all it took for extreme weather to take place in several parts of the planet.
You may have heard news about some remarkable weather occurrences over the past few weeks. For example, Arizona has been experiencing extreme heat this summer. Since it's the summer, we can of course expect temperatures to rise. However, temperatures shouldn't rise as high as they did in Arizona.
We now have another line of evidence that half a degree of increased global warming can have dire effects. Observational records have shown that in the past, this half-degree increase brought on an increase in extreme weather events. A new study reveals that two 20-year periods, 1960-1979 and 1991-2010, showed a half a degree of increase in global temperatures. Scientists also found that during these two periods, extreme weather became longer in duration and stronger in intensity.
Changes in climate are natural. However, extreme changes are not. As the findings of the study can attest, these bouts of extreme weather changes are beyond the limits of natural climate variations. The findings are not just projections of what could happen should global temperatures increase by half a degree. There are already observational records that show what has already happened due to that temperature increase. Scientists generally agree that observational records are more reliable than projections.
The records detailed how a half-degree increase in global temperatures affected the climate in certain places at certain times. The study showed that in a quarter of all land masses, summers grew hotter by a full 1ºC. The lowest temperatures in the winter, meanwhile, rose by over 2.5ºC. Extreme precipitation also grew by 10% in a quarter of all land masses. Hot spells also grew in duration by about a week and a half in half of all land masses, which puts these places in danger of experiencing forest fires.
This study thus makes it clear that even just a half-degree increase in global temperatures does matter. Therefore, efforts to keep the increase of global temperatures well below 2ºC are very much warranted.
The Paris climate accord is one such effort to keep global temperatures from rising too high. Nations in this accord have all agreed to keep the increase of global temperatures ideally at 1.5ºC. The Intergovernmental Panel on Climate Change (IPCC) will assess how feasible the 1.5ºC target is. Their report will also inform governments on what consequences we can avoid if we meet the target.
The IPCC will review this study, as well as many others, to analyze the significance of a half-degree increase in global temperatures. As the study showed, the implications of this seemingly small increase are quite significant. If we don't meet the 1.5ºC or even the 2ºC targets, we won't just experience extreme weather. The planet will also undergo several changes that will most likely affect many populations negatively. Keeping global temperatures at safe levels is definitely a very important challenge that humanity will have to take on in unity.
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