Climate change in 60 seconds | The Royal Society

Summary

The Earth's surface absorbs sunlight and re-emits it as heat, some of which is trapped by greenhouse gases like carbon dioxide and water vapor. Human activities, particularly burning fossil fuels, have raised atmospheric carbon dioxide levels by 40% since 1900, causing a 0.8°C rise in global temperature. This has led to ocean warming, sea level rise, shrinking snow and ice cover, and Arctic sea ice decline. If emissions continue unchecked, global temperatures could increase by 2.6°C to 4.8°C by the century's end, with significant consequences for both humanity and the environment.

Takeaways

• 🌞 The sun's rays reach Earth's surface, with some absorbed and re-emitted as heat.
• 🌍 Greenhouse gases like water vapor and carbon dioxide absorb and re-radiate some of this heat.
• 📈 An increase in greenhouse gases leads to more heat being trapped, warming the Earth.
• 🔥 Human activities, particularly burning fossil fuels, have increased atmospheric carbon dioxide by 40% since 1900.
• 🌡️ Global average surface temperature has risen by 0.8°C over this period.
• 🌊 Oceans have warmed, contributing to additional climate changes in recent decades.
• 🌊 Sea levels have risen due to climate change.
• ❄️ Snow and ice cover in the northern hemisphere has decreased, with a decline in Arctic sea ice.
• ⚠️ Unchecked emissions could lead to a temperature rise of 2.6°C to 4.8°C by the end of this century.
• 🚨 Even at the lower end of this temperature increase, there would be serious consequences for human societies and the natural world.

Q & A

What happens to the sun's rays when they reach the Earth's surface?

Some of the sun's rays are absorbed by the Earth's surface and re-emitted as heat.

What role do greenhouse gases play in trapping heat?

Greenhouse gases, such as water vapor and carbon dioxide, absorb and re-radiate some of the heat, preventing it from escaping into space.

How have human activities affected the concentration of greenhouse gases?

Human activities, especially the burning of fossil fuels, have increased atmospheric carbon dioxide concentrations by 40% since 1900.

How much has the global average surface temperature increased since 1900?

The global average surface temperature has increased by 0.8℃ since 1900.

What other climate changes have occurred in recent decades?

Recent decades have seen ocean warming, rising sea levels, decreasing snow and ice cover in the northern hemisphere, and a decline in Arctic sea ice.

What are the projected consequences if greenhouse gas emissions continue unchecked?

If emissions continue unchecked, global warming of 2.6℃ to 4.8℃ is expected by the end of this century.

What impact would even a low-end increase in temperature have?

Even a low-end temperature increase of 2.6℃ would have serious implications for both human societies and the natural world.

How does the increase in carbon dioxide affect sea levels?

The increase in carbon dioxide contributes to the warming of the oceans, which causes sea levels to rise due to thermal expansion and melting ice.

What is happening to snow and ice cover in the northern hemisphere?

Snow and ice cover in the northern hemisphere is decreasing, which contributes to further warming as reflective ice surfaces are replaced by darker, heat-absorbing surfaces.

Where can additional information about climate change be found?

More information about climate change can be found at royalsociety.org/climatechange or nas-sites.org/americasclimatechoices.