50 Fun Facts About Climate Change

Which greenhouse gas is the most abundant in Earth's atmosphere by average mole fraction?

It accounts for roughly 41–67% of the heat-trapping, but its level is set by temperature rather than by emissions, so it amplifies warming instead of driving it.

Which 1997 treaty committed industrialized countries to reduce greenhouse gas emissions?

The Kyoto Protocol was an international agreement adopted in 1997, legally binding developed countries to emission reduction targets. It represented a significant step in international climate policy.

At which Hawaiian observatory has CO2 been measured continuously since 1958, producing the Keeling Curve?

On 9 May 2013 the daily mean CO2 concentration recorded there passed 400 parts per million for the first time.

What is the largest human activity contributing to rising atmospheric carbon dioxide levels?

The combustion of fossil fuels (coal, oil, and natural gas) for energy, transportation, and industrial processes is the predominant human activity leading to increased carbon dioxide in the atmosphere.

What natural process has atmospheric gases trap heat and warm Earth's surface?

Nils Gustaf Ekholm gave the phenomenon its horticultural name in 1901, decades after the physics had been worked out.

Which greenhouse gas has a far higher 100-year warming potential than CO2 but a much shorter lifetime?

Methane is a potent greenhouse gas with a global warming potential significantly higher than CO2 over a 100-year period, but it has a much shorter atmospheric lifetime of about 12 years compared to CO2's much longer persistence.

Which American scientist showed in an 1856 paper that CO2 absorbs heat and could alter the climate?

Her paper appeared three years before John Tyndall's better-known experiments and was the first known physics paper by an American woman in a scientific journal.

Which scientist first quantitatively predicted, in 1896, the warming from doubling atmospheric CO2?

He calculated that doubling CO2 would raise temperatures by around 5–6 °C, and regarded the prospect as broadly benign.

Melting glaciers and polar ice sheets directly contribute to which significant environmental consequence?

As land-based glaciers and ice sheets melt due to rising global temperatures, the water flows into the oceans, directly increasing global sea levels.

What is the ongoing drop in seawater pH from absorbing excess carbon dioxide called?

Between 1950 and 2020 the average surface pH fell from about 8.15 to 8.05, roughly a 26% rise in hydrogen ion concentration.

Which of these energy sources emits no direct greenhouse gases when generating electricity?

Photovoltaic panels convert sunlight straight to electricity, while concentrated solar plants use mirrors to drive a conventional turbine.

What market mechanism caps total emissions and lets companies buy and sell allowances?

Cap and trade is an emissions trading system that sets a maximum limit on total emissions and allows companies to trade emission allowances, creating a financial incentive to reduce pollution.

Besides raising sea levels, what other major impact does warmer seawater have on marine ecosystems?

Rising ocean temperatures can cause coral bleaching, a phenomenon where corals expel vital algae, leading to their whitening and often death, which severely impacts biodiversity and marine habitats.

What term describes actions to limit greenhouse gas emissions or remove them from the atmosphere?

Climate mitigation involves strategies and actions to reduce the sources of greenhouse gas emissions or enhance the sinks that absorb them, thereby lessening the severity of future climate change.

What term describes ground frozen for at least two consecutive years, which releases carbon as it thaws?

The oldest of it has been continuously frozen for around 700,000 years, and thawing lets microbes break down organic matter locked up since the ice ages.

What feedback process accelerates warming when melting ice exposes darker surfaces that absorb more sunlight?

Fresh snow reflects most incoming sunlight while open water absorbs most of it, so each patch of lost sea ice lets more solar energy in.

Which process in the carbon cycle has plants absorb CO2 to create organic compounds?

Photosynthesis is the process by which green plants and other organisms use sunlight to synthesize foods from carbon dioxide and water, playing a crucial role in removing CO2 from the atmosphere as part of the carbon cycle.

What umbrella term covers heatwaves, droughts and heavy rainfall intensifying as the planet warms?

A key impact of climate change is the increasing occurrence and severity of extreme weather events, including prolonged heatwaves, more intense droughts, heavier rainfall, and stronger storms, affecting regions worldwide.

What is the term for capturing and storing atmospheric CO2 in forests, soils or rock?

Carbon sequestration involves capturing carbon dioxide from the atmosphere or from industrial sources and storing it in long-term reservoirs, such as forests, soils, or underground geological formations, to mitigate climate change.

Which 2015 international accord aims to keep global temperature rise well below 2 °C above pre-industrial levels?

It was adopted at COP21 in Paris in December 2015 and also pledges efforts to hold the increase to 1.5 °C.

Which synthetic gas has a 100-year warming potential roughly 23,500 times that of carbon dioxide?

SF6 is used as an insulator in high-voltage electrical switchgear and lingers in the atmosphere for thousands of years.

Which two United Nations bodies set up the Intergovernmental Panel on Climate Change in 1988?

Its first chair, Bert Bolin, was elected the same year, and the panel shared the 2007 Nobel Peace Prize with Al Gore.

What collective name is given to atmospheric constituents that absorb and emit the infrared Earth radiates?

Nitrogen and oxygen, which together make up 99% of dry air, are transparent to this radiation, so it is trace constituents that trap the heat.

Which nation has released the most cumulative carbon dioxide since the Industrial Revolution?

Between 1890 and 2007 the US accounted for about 28% of cumulative energy-related CO2 emissions, ahead of the EU's 23%, although China now leads annual emissions.

What term is a calculated index of the total greenhouse gas emissions an activity, product or country adds?

Some organisations prefer a broader name for the index to stress that every heat-trapping gas is counted, not just CO2.

What is a structure whose annual power use is matched by renewable generation on-site or procured off-site called?

The EU uses the related 'nearly zero-energy building' standard under its Energy Performance of Buildings Directive.

Which process in living cells oxidises carbohydrates back to carbon dioxide, the reverse of photosynthesis?

Global plant activity captures roughly 130 terawatts of energy, about eight times humanity's total power consumption, and this process gives much of it back.

Which NASA scientist's June 1988 Senate testimony raised broad public awareness of global warming?

He told senators he was 99 percent certain the Earth was warmer than at any time in the instrumental record.

What are the simulations that couple atmosphere, ocean, land and ice to project Earth's warming called?

Modern versions are often called earth system models because they include the carbon cycle and vegetation as well as the physics.

What term describes the long-term increase in the average temperature of the Earth's oceans?

Since 1970 the seas have taken up more than 90% of the excess heat in the climate system, which is why surface air temperatures understate the total.

What technology captures CO2 from a point source and injects it into deep geological formations?

Around a fifth of the CO2 captured so far has gone into dedicated storage, usually deep saline aquifers, with much of the rest used for enhanced oil recovery.

The IPCC's Sixth Assessment Report found that half of all species with long-term data had shifted their ranges in which direction?

Mountain species are moving upward instead, and the shifts have been recorded across insects, birds, fish and plants alike.

What term describes adjusting to a warming world's effects, rather than trying to prevent them?

Climate adaptation involves implementing strategies and measures to reduce vulnerability and build resilience to the unavoidable impacts of climate change, such as rising sea levels, extreme weather, and changes in agricultural patterns.

What concept holds that warming hits vulnerable populations hardest and calls for equitable responsibility?

Climate justice is a framework recognizing that climate change disproportionately affects vulnerable communities who have contributed least to the problem, advocating for fair distribution of both the burdens and benefits of climate action.

Which farming approach aims to restore degraded soils, boost biodiversity and store carbon?

Regenerative agriculture employs practices like cover cropping, no-till farming, and diverse rotations to improve soil health, increase biodiversity, and enhance the soil's capacity to draw down and store atmospheric carbon, thus mitigating climate change.

What financial instrument specifically funds projects with environmental or climate benefits?

Green bonds are a category of fixed-income securities that enable capital raising for projects that deliver environmental benefits, such as renewable energy installations, sustainable waste management, or green buildings.

The third most important greenhouse gas has a lifetime of about 109 years and a GWP 273 times CO2. Which is it?

Most of it comes from the denitrification part of the nitrogen cycle, boosted by fertilised farmland.

What term describes changes in the timing of seasonal events like flowering or migration due to climate change?

Phenological shifts refer to the observed changes in the timing of recurring biological events in plant and animal life cycles, such as earlier flowering or altered migration patterns, largely driven by a warming climate.

What weak compound forms when carbon dioxide dissolves in seawater, lowering its pH?

The extra hydrogen ions also lock up carbonate ions that corals and shellfish need to build their skeletons and shells.

What phenomenon makes built-up city centres significantly warmer than the surrounding countryside?

Luke Howard's first report of the effect found central London about 2.1 °C warmer at night than the surrounding countryside.

Roughly what was atmospheric CO2, in ppm, in the 10,000 years before the Industrial Revolution?

Ice cores show the level stayed between 180 and 280 ppm for the last 800,000 years, until the increase of the last 250 years.

What term refers to the fraction of solar radiation a surface reflects back into space?

Albedo quantifies the reflectivity of a surface, indicating the percentage of incoming solar radiation that is reflected back into space. Surfaces like snow and ice have high albedo, while oceans and forests have low albedo.

Which 1987 ozone treaty was the first global agreement ratified by every country?

Its 2016 Kigali Amendment extended it to hydrofluorocarbons, refrigerant gases with a strong warming effect of their own.

What is the goal where heat-trapping gases from human activity are balanced by removals called?

Reaching it means cutting emissions as far as possible and offsetting the remainder with removals such as new forests or engineered capture.

What term describes a critical threshold where a small change causes large, often irreversible, shifts?

A climate tipping point is a critical threshold in the Earth's climate system which, when exceeded, can lead to significant and often irreversible changes, such as the collapse of major ice sheets or large-scale ecosystem shifts.

What is planting a new forest on land not forested for a significant period called?

Reforestation, by contrast, means re-establishing forest on land that was cut down or lost to fire or storms.

What technology extracts carbon dioxide from the ambient atmosphere rather than from point sources?

Direct Air Capture (DAC) is an emerging technology that actively removes carbon dioxide from the atmosphere using specialized chemical processes, offering a way to address historical emissions and those from diffuse sources.

What process describes the degradation of productive land into arid or desert-like conditions?

Desertification is a severe form of land degradation where fertile land transforms into arid or desert-like conditions, primarily driven by climate change and unsustainable human land management practices.

Which 1992 treaty, opened for signature at the Rio Earth Summit, frames global greenhouse gas talks?

Its Conference of the Parties has met every year since the first session in Berlin in 1995.

What natural process breaks down dead organic matter, releasing CO2, and speeds up in warmth?

Microbes drive it and work faster in warmth, which is one reason thawing northern soils are giving up their stored carbon.