Shifts in the number, severity and location of extreme weather events are among the most important impacts of climate change.
Basic physics suggest that global warming should affect the occurrence of extreme weather. More energy is being added to the atmosphere, and as it warms, it can hold more water vapor.
On this basis alone, cold weather events should decline, heatwaves should increase, and there should be changes in the intensity and frequency of the dry and wet periods that cause droughts and floods.
However, the Earth’s climate system is very complex and natural variability, including El Niño and La Niña events, as well as important local and regional variations, make it difficult to separate out human influence on extreme weather events from other factors.
In addition, extreme weather is, by definition, relatively rare and it can take a long time to identify those that are a direct result of climate change.
While it is not always possible to attribute individual weather events to climate change, a recent review of scientific research on extreme weather concluded that there is already strong evidence that the number of extreme cold days around the world is decreasing, while hot days are on the rise, and patterns of rainfall in many regions are being altered as well.
Global sea level is also rising by more than 3mm per year, which means surges that are generated by storms over large bodies of water are also becoming higher. Surges are created ahead of storms by the impact of winds on the surface of the water.
There is still uncertainty about the extent to which climate change may already be affecting some other types of extreme weather events, such as tropical cyclones and tornadoes.
How much human populations are affected by changes in extreme weather also depends on whether they are exposed, by living in high-risk areas such as low-lying coastal areas, and vulnerable, due to, for example, poor quality housing.
Worldwide, the only reason why the number of reported deaths from weather-related events has decreased over the past 100 years is due to increased efforts to reduce vulnerability and exposure.
However, extreme weather can still kill large numbers of people, particularly in poor countries. There were up to 138,000 deaths when Cyclone Nargis hit Myanmar in 2008, for example. In total, more than 200 million people globally are killed or affected by weather-related events on average each year.
Here in the Philippines, another example is the 6,300 deaths attributed to Typhoon Yolanda or Haiyan in 2013, the 1,061 people that remain missing, and another 28,689 injured.
Damage and losses from weather-related events have increased markedly over the past 30 years, mostly due to an increase in the number and value of homes and businesses that are exposed to severe weather.
In the UK, the main ways in which climate change may already be affecting extreme weather are through the occurrence of very wet periods, leading to river and flash floods, and sea level rise, increasing the risk of coastal flooding.
If global warming of more than 2°C is not avoided through reductions in greenhouse gas emissions, impacts from extreme weather could overwhelm the capacity of some countries to cope, leading to wider impacts, from large-scale migration of populations to an increased risk of conflict.
In a recent list of countries and territories based on their carbon dioxide emissions due to certain forms of human activity, China – a close neighbor of the Philippines – came out on top by contributing approximately 25 percent of the world total, followed by the United States, the European Union, India, Russia and Japan.
The data only considers carbon dioxide emissions from the burning of fossil fuels and cement manufacture, but not emissions from land use, land-use change and forestry. The top 10 largest emitter countries account for 68.2 percent of the world total.
China emits more CO2 than the US and Canada put together – up by 171 percent since the year 2000. The US has had declining CO2 for two years running, but the last time the US had declining CO2 for 3 years running was in the 1980s. The UK is down one place to tenth on the list. The country is now behind Iran, South Korea, Japan and Germany. India is now the world’s third biggest emitter of CO2 – pushing Russia into fourth place.
But that is only one way to look at the data – and it doesn’t take into account how many people live in each country. If you look at per capita emissions, a different picture emerges where some of the world’s smallest countries and islands emit the most per person – the highest being Gibraltar with 152 tons per person.
The US is still number one in terms of per capita emissions among the big economies – with 18 tons emitted per person. China, by contrast, emits under six tons per person, India only 1.38, and for comparison, the whole world emits 4.49 tons per person.
Because of this recent data, reduction in global greenhouse gas emissions has not only become the goal of environmentalists, but also of pretty much every government in the world. This has resulted recently in the 2015 Paris Agreement on Climate Change.
Coming to know all this, when should we start realizing that we have to start changing the way we live our lives now? Isn’t it about time we stop using fossil fuel and adding CO2 to our atmosphere? Shouldn’t we already shift to using other renewable energy sources? Is it already too late?