- In 2019, atmospheric CO2 concentrations hit levels not seen on Earth for more than 3 million years.
- Warmer temperatures are translating to higher sea levels, as sea ice and glaciers melt and seawater undergoes thermal expansion as it warms.
Over the past two weeks, the COP26 climate summit has seen policymakers from all over the world assemble in Glasgow, Scotland, to make commitments aimed at keeping the goals of the Paris Agreement alive.
The Paris Agreement is a legally binding international treaty on climate change, which came into force in 2016 after being signed by 196 nations at COP21 the year before. It aims to limit global warming to "well below" 2 degrees Celsius above pre-industrial levels, with a key target of keeping temperature rises below 1.5 degrees Celsius.
The United States rejoined the Paris Agreement earlier this year after former President Donald Trump withdrew from the treaty.
According to researchers at Our World in Data, global carbon emissions have been rapidly rising since the mid-20th century, peaking in 2019 before falling slightly last year. The organization's data shows that emissions continued to rise after the Paris Agreement came into force.
The charts below compare CO2 emissions over time between some of the world's biggest polluters, as well as countries' share of annual global carbon emissions.
China, whose economic power has surged in recent decades, has seen its emission levels soar alongside massive rises in production, placing it ahead of the United States when it comes to releasing CO2 into the atmosphere. In 2020, the world's second-largest economy accounted for almost a third of global emissions from burning fossil fuels, according to Our World in Data.
Using statistics from Our World in Data, the chart below shows how much coal is burned per capita in some of the world's biggest coal-consuming economies.
When 28 countries joined an alliance aimed at phasing out coal during COP26 last week, the world's biggest burners of coal — China, the U.S. and India — were notably missing.
Coal, which fuels more than a third of the energy consumed worldwide, is the single biggest contributor to climate change.
One major consequence of burning fossil fuels has been a sustained increase in carbon dioxide levels in the Earth's atmosphere.
The chart below shows how CO2 concentrations in the atmosphere have risen in recent decades.
In 2019, atmospheric CO2 concentrations hit levels not seen on Earth for more than 3 million years. CO2 concentrations reached 415 parts per million in July, Our World in Data's numbers show — meaning that for every 1 million molecules of gas in the atmosphere, 415 were carbon dioxide.
Greenhouse gases like CO2 and methane trap heat in the Earth's atmosphere, and excessive levels of those gases are causing an energy imbalance that's leading to global warming. Greenhouse gases can also have other harmful effects such as altering the pH level of the ocean, and poor air quality has even been attributed to deaths in the U.K. and Canada.
The chart below shows how global land and sea temperatures have deviated from the 1951 to 1980 mean temperature over time.
In recent years, rising temperatures have been fueling deadly wildfires in the U.S., Australia and Europe, as well as floods and extreme weather events like hurricanes all over the world.
Warmer temperatures are translating to higher sea levels, as sea ice and glaciers melt and seawater undergoes thermal expansion as it warms.
Coastal states and small island nations, which are on the frontlines of the climate crisis, have been pleading for urgent action at COP26 to ensure the Paris Agreement's 1.5 degrees Celsius target is met.
Mia Mottley, prime minister of Barbados, told the climate summit that "1.5 is what we need to survive," while Costa Rican President President Carlos Alvarado Quesada told CNBC at COP26 that it was "a matter of life and death."
Meanwhile, the foreign minister of Tuvalu, an island in the South Pacific, filmed his COP26 speech while standing knee-deep in the ocean, a move intended to demonstrate his country's vulnerability to global warming.
International scientists estimate that since 1880, the global mean sea level has risen by around 21 to 24 centimeters (8 to 9 inches) — around a third of which has occurred within the last 25 years. Last year, global mean sea levels set new record highs.