The study, published in the journal Nature Climate Change, analyzed climate data from around the world and found that the difference between 1.5 degrees Celsius of warming and 2 degrees Celsius of warming could have a significant impact on the frequency and severity of extreme weather events.
For example, the study found that limiting warming to 1.5 degrees Celsius could reduce the number of people exposed to extreme heat waves by 50% in South Asia and 30% in Southeast Asia. It could also reduce the number of people exposed to droughts in the Mediterranean and Southern Europe by 15% and in Northeast Brazil by 35%.
In addition, the study found that limiting warming to 1.5 degrees Celsius could reduce the number of people exposed to floods in South Asia by 20% and in Southeast Asia by 10%.
"Our study shows that every fraction of a degree of warming matters when it comes to protecting people from the worst impacts of climate change," said lead author Dr. Friederike Otto, a climate scientist at the University of Oxford. "Limiting warming to 1.5 degrees Celsius is essential to avoiding the most severe and widespread impacts of climate change."
The findings of the study are consistent with the conclusions of the Intergovernmental Panel on Climate Change (IPCC), which has stated that limiting global warming to 1.5 degrees Celsius is necessary to avoid dangerous climate change.
"The evidence is clear that we need to act urgently to limit global warming to 1.5 degrees Celsius," said Dr. Otto. "We can't afford to wait any longer."
Why half a degree matters
There are several reasons why half a degree of warming matters when it comes to climate change.
First, half a degree of warming could lead to a significant increase in the frequency and intensity of extreme weather events. For example, a study by the World Meteorological Organization (WMO) found that the number of heat waves has increased by a factor of two since 1950 and the number of heavy precipitation events has increased by a factor of three. These trends are expected to continue as the planet warms, and they could have a devastating impact on human health and infrastructure.
Second, half a degree of warming could also lead to a significant loss of biodiversity. For example, a study by the International Union for Conservation of Nature (IUCN) found that 20% of all plant and animal species are at risk of extinction due to climate change. This includes species that are important for human survival, such as pollinators and food crops.
Third, half a degree of warming could also lead to a significant increase in sea level rise. For example, the IPCC has projected that sea levels could rise by 0.26-0.77 meters by 2100 if global warming is limited to 1.5 degrees Celsius, but by 0.45-1.1 meters if warming reaches 2 degrees Celsius. This could have a devastating impact on coastal communities, particularly in developing countries.
For all of these reasons, half a degree of warming matters when it comes to climate change. It is essential that we take action to limit global warming to 1.5 degrees Celsius to avoid the worst impacts of climate change.
