Get a complete overview of climate change by understanding its definition, causes, effects, and connection to global warming with actionable insights for 2025 and beyond.
Climate change has become the defining environmental challenge of our time.
According to UK Government climate data:
“Measurements of the average temperature at the Earth’s surface show it has risen by about 1.34 to 1.41°C since the pre-industrial period,” with the last decade (2015-2024) being the warmest 10 years on record.”
Understanding what climate change is, what causes it, and how it affects us has never been more important. This comprehensive guide explains climate change in simple terms, from basic definitions to the science behind global warming, greenhouse gases, and the impacts we’re already experiencing worldwide.
Source: UK Government – Climate Change Explained
What is Climate Change?
Climate change refers to long-term shifts in temperatures and weather patterns across the planet. While the climate has changed throughout Earth’s history due to natural factors, the current climate change is primarily caused by human activities, especially burning fossil fuels like coal, oil, and gas.
United Nations explains that:
“fossil fuels, coal, oil, and gas are by far the largest contributors to global climate change, accounting for over 75 per cent of global greenhouse gas emissions and nearly 90 per cent of all carbon dioxide emissions.”
These emissions trap heat in Earth’s atmosphere, causing the planet to warm, a process called global warming. It is also important to understand that climate is different from weather.
Weather refers to short-term atmospheric conditions, whether it’s sunny, rainy, or snowy today. Climate describes average weather patterns over long periods, typically 30 years or more. When we talk about climate change, we’re talking about long-term shifts in these patterns.
Understanding Global Warming vs. Climate Change
Many people use “global warming” and “climate change” interchangeably, but they have slightly different meanings:
Global Warming specifically refers to the increase in Earth’s average surface temperature caused by rising levels of greenhouse gases.
NASA explains that:
“Scientists attribute the global warming trend observed since the mid-20th century to the human expansion of the greenhouse effect, warming that results when the atmosphere traps heat radiating from Earth toward space.”
Climate Change is the broader term encompassing not just warming temperatures but all the changes happening to our planet’s climate system. These include:
- Rising sea levels
- Melting ice sheets and glaciers
- More frequent extreme weather events
- Shifting precipitation patterns
- Ocean acidification
- Changes to ecosystems and wildlife habitats
According to UK Government data:
“Climate change is happening and is due to human activities; along with warming, many other changes are occurring such as melting polar ice, rising sea levels and more frequent floods, droughts and heatwaves.”
So while global warming is one major aspect of climate change, climate change includes all the consequences of that warming and other changes to Earth’s climate system.
Source: European Commission – Causes of Climate Change
The Science Behind Climate Change: The Greenhouse Effect
To understand climate change, you need to understand the greenhouse effect, a natural process that makes Earth habitable but becomes dangerous when intensified by human activities.
How the Greenhouse Effect Works
NASA explains that:
“life on Earth depends on energy coming from the Sun. About half the light energy reaching Earth’s atmosphere passes through the air and clouds to the surface, where it is absorbed and radiated in the form of infrared heat.”
Here’s what happens next:
- Energy Arrives: Sunlight reaches Earth and passes through the atmosphere
- Energy Absorbed: Earth’s surface absorbs this energy and warms up
- Heat Radiated: The warmed surface radiates heat back toward space
- Greenhouse Gases Trap Heat: Greenhouse gases in the atmosphere absorb this outgoing heat and re-radiate it in all directions, including back to Earth’s surface
- Planet Warms: This trapped heat keeps Earth warm enough for life
Without the greenhouse effect, Earth would be too cold for most life about -18°C (0°F) on average instead of the current 15°C (59°F). However, human activities have intensified this natural process by adding excessive amounts of greenhouse gases to the atmosphere.
Key Greenhouse Gases
According to NASA’s climate research, five key greenhouse gases are carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, and water vapor. Let’s examine the most important ones:
Carbon Dioxide (CO2): The primary greenhouse gas emitted by human activities. EPA reports that:
“atmospheric carbon dioxide concentrations have increased by more than 40 percent since pre-industrial times, from approximately 280 parts per million (ppm) in the 18th century to 419 ppm in 2023.”
Methane (CH4): A more powerful greenhouse gas than CO2 but with a shorter atmospheric lifetime. NASA notes that:
“methane comes from plant-matter breakdown in wetlands and is also released from landfills and rice farming. Livestock animals emit methane from their digestion and manure.”
Nitrous Oxide (N2O): According to NASA:
“A potent greenhouse gas is produced by farming practices, released during commercial and organic fertilizer production and use.”
Source: NASA – Causes of Climate Change
Major Causes of Climate Change
Understanding what causes climate change helps us identify solutions. Let’s examine the primary drivers:
Burning Fossil Fuels
The combustion of fossil fuels is the biggest contributor to climate change. CERAH explains that:
“the process of burning fossil fuels such as coal, oil and natural gas releases large amounts of carbon dioxide (CO2) into the atmosphere. CO2 is the main greenhouse gas responsible for the effects of global warming.”
Fossil fuels power:
- Electricity and heat production: Coal and natural gas power plants generate most of the world’s electricity
- Transportation: Cars, trucks, ships, and planes run primarily on petroleum products
- Manufacturing and industry: Factories burn fossil fuels for energy to produce goods
- Buildings: Heating and cooling homes and offices
UN data shows that:
“Transport accounts for nearly one quarter of global energy-related carbon dioxide emissions, making it a major contributor to climate change.”
Deforestation and Land Use Changes
Forests are crucial carbon sinks as they absorb CO2 from the atmosphere and store it in trees, vegetation, and soil.
European Commission notes that:
“Trees help to regulate the climate by absorbing CO2 from the atmosphere. When they are cut down, that beneficial effect is lost, and the carbon stored in the trees is released into the atmosphere.”
EOS explains that:
“Approximately 4.8 billion tons of carbon dioxide are released into the Earth’s atmosphere as a result of deforestation each year, particularly in tropical areas.”
Agriculture and Food Production
Modern agriculture contributes significantly to climate change. UN reports that:
“producing food causes emissions of carbon dioxide, methane, and other greenhouse gases”
This is accomplished through:
- Deforestation for farmland and grazing
- Digestion by cows and sheep producing methane
- Production and use of fertilizers and manure
- Use of fossil fuels to run farm equipment
- Rice paddy cultivation releasing methane
Livestock farming is particularly emission intensive. Cattle produce substantial methane during digestion, and raising livestock requires vast amounts of land, water, and feed.
Industrial Processes and Manufacturing
UN data shows that :
“manufacturing and industry produce emissions, mostly from burning fossil fuels to generate the energy needed to make things like cement, iron, steel, electronics, plastics, clothes, and other goods.”
Industrial processes also release greenhouse gases directly. Cement production, for instance, generates CO2 both from burning fuel and from chemical reactions in cement manufacturing.
Source: UN – Causes and Effects of Climate Change
Impacts and Effects of Climate Change
Climate change affects every aspect of our planet and our lives. Let’s examine the major impacts:
Rising Global Temperatures
NASA reports that:
“as greenhouse gas concentrations rise, so does the global surface temperature. The last decade, 2015-2024, is the warmest on record. Since the 1980s, each decade has been warmer than the previous one.”
European Commission data shows that:
“2015-2024 was the warmest decade recorded, with global average temperature reaching 1.55°C above pre-industrial levels in 2024. Human-induced global warming is presently increasing at a rate of 0.25°C per decade.”
Temperature increases aren’t uniform globally. The Arctic is warming more than twice as fast as the global average, a phenomenon called Arctic amplification. This rapid warming has profound implications for ice sheets, sea levels, and global weather patterns.
Extreme Weather Events
Climate change is making extreme weather more frequent and severe. UN reports that:
“destructive storms have become more intense and more frequent in many regions. As temperatures rise, more moisture evaporates. This exacerbates extreme rainfall and flooding, causing more destructive storms.”
Specific impacts include:
- Heat Waves: More frequent, longer-lasting, and more intense heat waves
- Droughts: Extended dry periods affecting water supplies and agriculture
- Hurricanes and Cyclones: More powerful tropical storms fed by warmer ocean waters
- Flooding: Increased heavy rainfall events leading to catastrophic flooding
- Wildfires: Longer fire seasons with more frequent and severe fires
Melting Ice and Rising Sea Levels
Warming temperatures are melting glaciers, ice sheets, and sea ice at alarming rates. This has two major consequences:
- Sea Level Rise: As ice melts and warmer ocean water expands, sea levels rise, threatening coastal communities worldwide
- Loss of Reflectivity: Ice reflects sunlight back to space. When it melts, darker ocean or land surfaces absorb more heat, accelerating warming—a feedback loop that intensifies climate change
Ocean Changes
Oceans absorb much of the excess heat and CO2 from the atmosphere. This causes:
- Ocean Warming: Affecting marine ecosystems and increasing storm intensity
- Ocean Acidification: CO2 dissolved in seawater forms carbonic acid, harming coral reefs and marine life
- Disrupted Ocean Currents: Changing temperature and salinity patterns affect major ocean currents that regulate global climate
Impacts on Ecosystems and Biodiversity
Climate change threatens ecosystems and species worldwide:
- Coral reefs bleaching and dying from warming waters
- Species shifting their ranges toward cooler regions
- Timing mismatches between species and their food sources
- Increased extinction risk for vulnerable species
- Changes to forests, grasslands, and other biomes
Human Health and Well-being
Climate change directly affects human health through:
- Heat-related illnesses and deaths
- Worsened air quality from increased pollution and wildfire smoke
- Spread of vector-borne diseases like malaria to new regions
- Food and water insecurity
- Mental health impacts from climate-related disasters
- Forced migration and climate refugees
The Role of Science: IPCC, UNFCCC, and NOAA
Several major scientific organizations lead climate change research and policy:
Intergovernmental Panel on Climate Change (IPCC)
The IPCC is the UN body for assessing climate science. The UK Government states that:
“the UK Government fully supports the work of the IPCC. It regards the IPCC’s assessments as the most authoritative view on the science of climate change.”
IPCC reports undergo rigorous review by thousands of scientists and government representatives. Their findings drive international climate policy, including the Paris Agreement’s temperature targets.
United Nations Framework Convention on Climate Change (UNFCCC)
The UNFCCC provides the institutional framework for international climate negotiations. It organizes annual Conference of Parties (COP) meetings where countries negotiate climate action.
National Oceanic and Atmospheric Administration (NOAA)
NOAA monitors climate conditions, maintains long-term climate records, and conducts climate research. Their data helps track climate change in real-time and understand its impacts.
These organizations provide the scientific foundation for understanding climate change and developing solutions. Their work shows overwhelming scientific consensus: climate change is real, it’s caused by human activities, and urgent action is needed.
What Can We Do About Climate Change?
While climate change presents enormous challenges, solutions exist:
Reduce Greenhouse Gas Emissions
- Transition to renewable energy (solar, wind, hydroelectric)
- Improve energy efficiency in buildings and transportation
- Electrify transportation and switch to electric vehicles
- Support sustainable agriculture and reduce food waste
Protect and Restore Natural Carbon Sinks
- Stop deforestation and protect existing forests
- Restore degraded forests and plant trees
- Protect wetlands, peatlands, and other carbon-rich ecosystems
- Support regenerative agriculture
Individual Actions
- Reduce energy consumption at home
- Choose sustainable transportation
- Eat more plant-based foods
- Support climate-friendly businesses and policies
- Educate others about climate change
Conclusion
Climate change represents humanity’s greatest environmental challenge, but understanding it is the first step toward addressing it. The science is clear that human activities, primarily burning fossil fuels and deforestation, are causing rapid warming of our planet with far-reaching consequences.
The good news is we have the knowledge and technology to address climate change. What we need is collective action from individuals, businesses, and governments to transition to clean energy, protect natural carbon sinks, and build resilience to climate impacts we can no longer avoid.
Every action matters. By understanding climate change and taking steps to reduce emissions and support solutions, we can help protect our planet for current and future generations. The time to act is now.
Glossary
Atmosphere: The layer of gases surrounding Earth
Carbon Sink: Natural system that absorbs and stores carbon dioxide (forests, oceans)
Fossil Fuels: Coal, oil, and natural gas formed from ancient organic matter
Global Warming: Increase in Earth’s average surface temperature
Greenhouse Effect: Natural process where atmospheric gases trap heat
Greenhouse Gases: Gases that trap heat in the atmosphere (CO2, methane, nitrous oxide)
IPCC: Intergovernmental Panel on Climate Change—UN body assessing climate science
Net Zero: Balance between greenhouse gases emitted and removed from atmosphere
Paris Agreement: International treaty limiting global warming to well below 2°C
UNFCCC: UN Framework Convention on Climate Change—international climate policy body
Frequently Asked Questions
What is the difference between climate and weather?
Weather describes short-term atmospheric conditions (today’s temperature and precipitation), while climate describes average weather patterns over decades or longer periods.
Is climate change real?
Yes. UK Government confirms that “it is unequivocal that human influence has warmed the atmosphere, ocean, and land,” with overwhelming scientific evidence from multiple independent sources.
What causes climate change?
Human activities, primarily burning fossil fuels for energy and deforestation, release greenhouse gases that trap heat in the atmosphere, causing global warming and climate changes.
How much has the planet warmed?
Earth’s average surface temperature has risen 1.34 to 1.41°C since pre-industrial times, with most warming occurring in recent decades.
Can we still stop climate change?
We can’t completely stop it, but we can limit future warming by rapidly reducing greenhouse gas emissions. According to UK Government “limiting global warming to 1.5°C or 2°C requires reduced global carbon dioxide emissions to at least net zero by the 2050s and 2070s, respectively.”
