IN SHORT: Most of the world's people live in the northern hemisphere, the half of the globe above the equator that includes the populous countries of India, China and Nigeria. So it's no surprise that higher temperatures caused by human activity have been recorded there.
"'Global warming' is not global. The northern hemisphere is cooling."
That's the headline of a May 2023 article on the Exposé, a UK-based website known for publishing false information.
"When climate alarmists market their 'catastrophic anthropogenic climate change' agenda, it is, to a large degree, on the presumption that the Western World is causing 'global warming'," the article begins.
"The largest countries of the West are located in the northern hemisphere. A Twitter user has pointed out an anomaly in monthly temperature changes demonstrating 'global warming' is not global nor is the northern hemisphere, and therefore the West, experiencing 'warming'."
Before we examine this claim, let's clarify a few things.
What is global warming?
By "anthropogenic climate change", the Exposé means changes to Earth's climate caused by human activity from at least the start of the first industrial revolution in the late 1700s.
This change in climate - shown by rising seas levels, melting glaciers, heatwaves and drought - is caused by global warming. The warming is a result of greenhouse gases released into the atmosphere by our factories, power stations, cars and more.
Greenhouse gases include carbon dioxide, methane and nitrous oxide. They're called "greenhouse" because they trap the heat from the sun in Earth's atmosphere similar to the way a greenhouse keeps plants warm in cold weather.
There has been debate about whether global warming is a result of human activity or is just part of Earth's natural climate cycle. But almost all scientists agree that recent warming and changes to the planet's climate have been caused by people.
The northern and southern hemispheres
Earth can be divided into the northern hemisphere north of the equator and the southern hemisphere south of the equator.
But is the northern hemisphere really cooling?
Misinterpreting the data
The Exposé bases its article on a May 2023 tweet by @FrankfurtZack, a Twitter user from Germany with more than 42,000 followers.
The tweet includes two graphs from Our World in Data, a project of the Global Change Data Lab in the UK.
The graphs show changes in temperature measured in the northern and southern hemispheres from November 2014 to March 2023.
Both have the header: "Global warming: monthly temperature anomaly. The combined land-surface air and sea-surface water temperature anomaly is given as the deviation from the 1951-1980 mean."
This might sound confusing, but the graphs simply show significant changes in the monthly average temperatures of the two hemispheres, measured against average temperatures recorded from 1951 to 1980.
And both graphs indicate an increase in temperature in both the northern and southern hemispheres from November 2014 to March 2023.
The axis of the southern hemisphere graph runs from a positive 0.4°C (temperature in degrees Celsius) to 0.9°C. None of the data points show a temperature lower than the 1951 to 1980 average.
The northern hemisphere graph runs from a higher 0.8°C to 1.8°C. This indicates that the northern hemisphere has warmed more than the south.
The Exposé includes the graphs in its article.
"What these graphs appear to show is that the northern hemisphere is cooling while the southern hemisphere is warming," it reads. "In other words, the hemisphere where the largest Western nations that are committing 'emissions crimes' are located is cooling."
The graphs don't show anything of the sort. The Exposé isn't only wrong: it interprets the data backwards.
A quick trip to the Our World in Data website shows why. Its graph plotting anomalies in both the northern and southern hemispheres shows the north's temperatures have been higher than the south's.
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While all of the planet is warming, temperatures in the northern hemisphere have been rising more rapidly than in the south. This is clearly shown in a more comprehensive graph of recorded temperatures from January 1880 to April 2023.
In March 2023 Berkeley Earth, a research nonprofit based in the US state of California, released new data on global temperature variations. The organisation was set up in 2013 to address the concerns of climate change sceptics.
Berkeley Earth has produced a video visualising the data.
It shows that while higher temperatures have been recorded across the globe, they are more common and intense in the northern hemisphere.
Berkeley Earth's data has also been used in interactive visualisations published by the Washington Post in December 2022. They show the same thing.
