What is the difference between 'global warming' and 'climate change'?
Global warming refers only to the increase in global average surface temperature, while climate change includes both global warming and its effects on Earth's climate system, such as changes in precipitation.
What is the main human activity driving modern-day climate change?
Burning fossil fuels (coal, oil, and natural gas) since the Industrial Revolution is the main driver, releasing greenhouse gases that trap heat.
How much has atmospheric CO₂ increased since pre-industrial times?
Earth's atmosphere now has roughly 50% more carbon dioxide than at the end of the pre-industrial era.
What are three major greenhouse gases released by human activities?
Carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) are key greenhouse gases from fossil fuel use, agriculture, and deforestation.
How do greenhouse gases warm the lower atmosphere?
They absorb some of the heat that the Earth radiates after it warms from sunlight, trapping heat in the atmosphere.
What is the current global temperature anomaly relative to 1850?
2024 was the warmest on record at +1.60 °C above the average from 1850.
What are two observed impacts of climate change on the environment?
Heat waves and wildfires are becoming more common; also, amplified Arctic warming causes permafrost thaw, glacier retreat, and sea ice decline.
How does climate change affect species?
Rapid environmental change in mountains, coral reefs, and the Arctic forces many species to relocate or become extinct.
What are two long-term effects of climate change that will persist for centuries?
Ocean heating and ocean acidification, as well as sea level rise, will continue even if future warming is minimized.
How does climate change threaten human societies?
It increases flooding, extreme heat, food and water scarcity, disease, economic loss, and can lead to human migration and conflict.
What is the Paris Agreement's goal for limiting warming?
Nations agreed to keep global warming 'well under 2 °C' above pre-industrial levels.
What would be the warming outcome under current Paris Agreement pledges?
Global warming would still reach about 2.8 °C by the end of the century.
Name three energy sources that do not produce significant carbon pollution.
Wind, solar, and hydro (also nuclear) are low-carbon energy sources.
How can carbon be removed from the atmosphere?
By increasing forest cover and using farming methods that store carbon in soil.
What is a climate tipping point?
A threshold beyond which climate change triggers large, often irreversible changes, such as melting the entire Greenland ice sheet.
What is the term for climate change caused by human activities?
Anthropogenic climate change.
What are climate proxies?
Indirect evidence of past climate, such as tree rings and ice cores, used to infer temperatures before thermometer records.
How much higher were sea levels during the Last Interglacial (125,000 years ago) compared to today?
Sea levels were 5 to 10 metres higher than today.
How much lower were sea levels during the last glacial maximum (20,000 years ago)?
Sea levels were over 125 metres lower than today.
What is the role of solar radiation in the global climate system?
Solar radiation is the primary energy source that warms Earth's surface; the atmosphere, ocean, and land interact to distribute and regulate this energy.
What is ocean acidification and what causes it?
Ocean acidification is the decrease in pH of seawater caused by absorption of excess CO₂ from the atmosphere.
Why are poorer communities more vulnerable to climate change?
They have the least ability to adapt and are responsible for a small share of global emissions, yet face the greatest risks.
What is the difference between climate change mitigation and adaptation?
Mitigation reduces greenhouse gas emissions to limit warming; adaptation adjusts to the effects of climate change (e.g., flood controls, drought-resistant crops).
What does the term 'global heating' emphasize?
It emphasizes the ongoing warming trend, often used to highlight the urgency of climate change.