Long-term shifts in temperatures and weather patterns indicate climate change, which can affect our health, ability to grow food, housing, safety and livelihood.
Some of us are already more vulnerable to climate impacts, such as those living in small island nations and other developing countries.
Conditions like sea-level rise and saltwater intrusion have advanced to the point where whole communities have had to relocate, and protracted droughts are putting people at risk of famine.
In future, the number of “climate refugees” is expected to rise, according to the United Nations (UN).
That said, long-term shifts in temperatures and weather patterns may be natural, such as through variations in the solar cycle.
But since the 1800s, human activities have been the main driver of climate change, primarily due to burning fossil fuels like coal, oil and gas.
Burning fossil fuel generates greenhouse gas emissions that act like a blanket wrapped around the Earth, trapping the sun’s heat and raising temperatures.
Examples of greenhouse gas emissions that are causing climate change include carbon dioxide and methane. These come from using gasoline for driving a car or coal for heating a building, for example.
Clearing land and forests can also release carbon dioxide. Landfills for garbage are a major source of methane emissions.
Industry and transport of all forms are among the main emitters.
Greenhouse gas concentrations are at their highest levels in 2mn years, UN noted in a recent report.
And emissions continue to rise. As a result, the Earth is now about 1.1C warmer than it was in the late 1800s. The last decade (2011-2020) was the warmest on record.
Many people think climate change mainly means warmer temperatures. But temperature rise is only the beginning of the story. Because the Earth is a system, where everything is connected, changes in one area can influence changes in all others.
The consequences of climate change now include, among others, intense droughts, water scarcity, severe fires, rising sea levels, flooding, melting polar ice, catastrophic storms and declining biodiversity.
In a 2018 UN report, thousands of scientists and government reviewers agreed that limiting global temperature rise to no more than 1.5C would help us avoid the worst climate impacts and maintain a liveable climate.
Yet the current path of carbon dioxide emissions could increase global temperatures by as much as 4.4C by the end of the century.
The emissions that cause climate change come from every part of the world and affect everyone, but some countries produce much more than others.
The 100 least-emitting countries generate 3% of total emissions, while the 10 countries with the largest emissions contribute 68%.
Climate action requires significant financial investments by governments and businesses. But climate inaction is vastly more expensive.
One critical step, the UN emphasised is for industrialised countries to fulfil their commitment to provide $100bn a year to developing countries so they can adapt and move towards greener economies.
Clearly, everyone must take climate action, but people and countries creating more of the problem have a greater responsibility to act first.
Viewpoint
