The Ultimate Glossary of Climate Change Terms (2025 Edition)

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Welcome to your go-to glossary for navigating the evolving language of climate change in 2025. Whether you’re a student, writer, educator, or just climate-curious, these quick definitions will help you keep up with the conversation—from policy and tech to nature and solutions. Use this A–Z guide to stay informed, connected, and ready to engage.

A

• Adaptation: Changes and planning aimed at reducing damage from climate impacts—like building flood defences or adjusting farming practices. 

• Afforestation: Planting trees in areas where there were none before to help absorb CO₂ from the air. 

• Anthropogenic: Caused by human activities, especially referring to climate change driven by fossil fuel use and industrialisation.

B

• BECCS (Bioenergy with Carbon Capture and Storage): A process using plants for energy while capturing and storing the CO₂, preventing it from reaching the atmosphere. 

• Biodiversity Loss: The decline in plant and animal species, often due to climate change, pollution, or habitat destruction.

C

• Carbon Capture and Storage (CCS): Technology that collects CO₂ from industrial sources and stores it underground to prevent emissions. 

• Carbon Credit: A tradable certificate allowing the emission of a certain amount of CO₂. Used in emissions trading schemes. 

• Carbon Footprint: The total greenhouse gas emissions caused directly or indirectly by an individual, organisation, or activity. 

• Carbon Neutral: When any emitted carbon is balanced by actions to remove or offset the same amount from the atmosphere. 

• Circular Economy: A system where resources are reused, repaired, or recycled to reduce waste and emissions. 

• Climate Change: Long-term changes in weather and temperature patterns, primarily driven by human activities. 

• Climate Crisis: An urgent framing of climate change, highlighting its accelerating impacts on ecosystems and human life. 

• Climate Finance: Funding provided to reduce emissions and support climate resilience, especially in developing countries. 

• Climate Justice: A principle that addresses the unequal impacts of climate change and calls for fair, inclusive solutions.

D

• Direct Air Capture: Technology that pulls CO₂ directly from the air and stores it. Still being tested at large scales. 

• Drought: Extended periods without rainfall, leading to dry soil, water shortages, and stressed ecosystems.

E

• Ecosystem-Based Adaptation: Using nature-based solutions—like forests or wetlands—to reduce climate-related risks such as flooding or extreme heat. 

• Emissions: Greenhouse gases released into the atmosphere from sources like fossil fuels and agriculture. 

• Energy Efficiency: Getting the same output using less energy—like LED bulbs or insulated buildings.

F

• Flooding: Overflowing water caused by storms, heavy rain, or rising sea levels—becoming more common with climate change. 

• Fossil Fuels: Coal, oil, and natural gas. Burning them is the main driver of global CO₂ emissions.

G

• Global Warming: The increase in Earth’s average surface temperature due to rising greenhouse gas levels. 

• Greenhouse Effect: The process by which greenhouse gases trap heat in the atmosphere—natural, but intensified by human activity. 

• Greenhouse Gases (GHGs): Gases like CO₂, methane, and nitrous oxide that trap heat and drive climate change.

H

• Heatwave: A prolonged period of excessive heat, often dangerous to health and made more common by climate change. 

• Hydropower: Renewable energy generated from moving water—like rivers and dams. Can disrupt ecosystems if not managed carefully.

I

• Injection Well: A deep well used to store captured CO₂ underground as part of carbon removal strategies. 

• IPCC (Intergovernmental Panel on Climate Change): The UN body that reviews climate science and advises governments worldwide.

J

• Just Transition: The concept of moving to a green economy in a way that supports workers and communities, especially those reliant on fossil fuels.

K

• Kyoto Protocol: A 1997 international treaty that committed countries to reduce emissions. Predecessor to the Paris Agreement.

L

• Low-Carbon Economy: An economy built on renewable energy, energy efficiency, and low-emission technologies.

M

• Maladaptation: A climate solution that accidentally causes more harm than good—like increasing flood risks nearby. Mitigation: Actions to reduce or prevent greenhouse gas emissions, such as switching to clean energy or reforestation.

N

• Natural Capital: Natural resources like forests, air, and water that support human life and economies. Net Zero: When greenhouse gas emissions are balanced out by removals, resulting in no net increase in the atmosphere.

O

• Offsetting: Paying for activities like tree planting or clean energy to compensate for one’s own emissions.

P

• Paris Agreement: The 2015 international treaty in which countries pledged to limit global warming to well below 2°C. Permafrost: Permanently frozen ground in polar regions. When it melts, it can release methane and CO₂.

Q

• Quantified Goal (in Climate Finance): A set financial target for supporting climate solutions, usually agreed among nations.

R

• Renewable Energy: Energy from natural sources that don’t run out—like solar, wind, and hydro. Resilience: The ability of communities or systems to recover quickly from climate shocks like storms or droughts.

S

• Sea-Level Rise: Oceans are rising due to melting ice and warming water, threatening coastal areas worldwide. Sustainability: Using resources in a way that meets today’s needs without harming future generations' ability to do the same.

T

• Tipping Point: A moment when climate systems shift suddenly and irreversibly—like ice sheet collapse or rainforest dieback.

U

• Urban Heat Island: Cities are often hotter than surrounding areas due to concrete and lack of greenery absorbing heat.

V

• Vulnerability: How sensitive or exposed something is to climate risks, and how well it can adapt or cope.

W

• Wildfire: Uncontrolled fires in forests or grasslands, often worsened by drought and extreme heat.

X

• Xeriscaping: Landscaping that uses drought-resistant plants to conserve water—especially useful in arid regions.

Y

• Youth Climate Action: Young people leading movements, campaigns, and innovations for urgent climate solutions.

Z

• Zero-Carbon Energy: Energy sources that produce no greenhouse gas emissions—like solar, wind, and nuclear.

This glossary is built to help you follow climate news, join the conversation, or write with confidence. It’s not exhaustive—but it’s a solid place to start.