Energy from the Sun

The energy from the Sun varies over time due to activity on the Sun's surface. Also, slight shifts in the tilt of the Earth and the shape of its orbit around the Sun affects the amount of the Sun's energy that reaches the surface of the Earth. Within decades, the energy could change by 1%, but over thousands of years the variations could be larger. What does the model predict the Earth's average temperature would be if there was no energy from the Sun (0%)?

Greenhouse gases

Energy from the Sun warms the Earth. As the Earth's temperature increases, more heat is radiated back into space (represented by the orange arrows on the model). Greenhouse gases (like carbon dioxide and methane) trap heat radiated from the Earth. Some of this heat is directed back to the Earth’s surface and as a result the surface temperature of the Earth increases. What does the model predict the Earth's temperature would be if there were no Greenhouse gases?

Earth's reflectivity

Some of the energy from the Sun does not reach the Earth's surface and warm it up but is reflected back into space. Bright white surfaces like snow, ice and clouds are good at reflecting sunlight. Dark surfaces like the ocean reflect less sunlight and so more energy is absorbed by the Earth and warms it up. What does the model predict will happen to the Earth's temperature if reflectivity decreases?

Climate model

Earth’s averagesurface temperature

Just right

☀️

Energy from the Sun

0%110%

CO₂

Greenhouse gases

Like CO₂ trapping heat

NoneLots

❄️

Earth's reflectivity

Ice & clouds bouncing sunlight

0%100%

(Image not to scale)