How do scientists measure global heating?

According to scientists, Earth has already heated up by about 1.1°C since 1900. If temperatures rise by a further 2°C or more, we could see more extreme weather like floods and heatwaves. That’s why we’re keeping a close watch on Earth’s temperature. But how do we do it?

Weather stations across the globe

First, we need to know how hot or cold Earth is right now. But Earth isn’t the same temperature everywhere - in some deserts, it can reach 45°C, while at the North Pole, it might be as cold as –10°C. To really understand Earth’s temperature, we need to measure it in lots of places all over the world.

That’s what weather stations do. These are little huts packed with instruments set up all across the globe, from Dubai in the Middle East to the South Pole. These stations measure temperature, solar radiation, wind speed and more.

Average temperature is rising

Every day, weather stations send their data to meteorologists. They use computers to gather all the temperatures from around the world and calculate the average. Right now, Earth’s average temperature is 15°C.

How do we know the Earth is getting warmer? Scientists have been keeping weather records since about 1850. From those old records, we know that in 1900, the average temperature was 14°C. Today, it’s about 15°C - so that’s 1 degree warmer!

Sea and ice

It’s not just rising temperatures that show Earth is heating up. Oceanographers have detected increasing levels of carbon dioxide in the sea. That’s a greenhouse gas - it traps heat like a blanket around the planet. The more greenhouse gases we have, the hotter Earth gets. Glaciologists - scientists who study ice - can see the planet is heating up too, as glaciers, those giant rivers of ice on mountains, are melting faster than ever.

It’s a sign we need to take action, before Earth gets too hot to handle.

Asnwered by Melanie Metz