Climate Change Facts: What You Need to Know
Climate change is one of the defining challenges of our time. Understanding the key facts - from what's happening to our planet to how it affects people, communities and wildlife - is essential for grasping why this matters and what we can do about it.
The evidence is clear: human activities are changing Earth's climate, and the effects are already being felt worldwide.
Here are the essential facts about climate change and its effects, backed by the latest scientific data.
Updated in January 2026
10 Key Climate Change Facts
1. The Earth is Getting Warmer
2024 was the warmest year on record, with global temperatures 1.53°C above pre-industrial levels (1850-1900). This marks the second consecutive year setting a new temperature record. The past decade has been the hottest since records began in the mid-1800s, and the 10 warmest years ever recorded have all occurred since 2014.
2. Human Activity is the Main Cause
Scientists estimate that human activities are responsible for approximately 100% of the warming observed since 1950. Burning fossil fuels, deforestation and industrial processes release greenhouse gases that trap heat in the atmosphere. Carbon dioxide levels reached 422.8 parts per million in 2024 - a 52% increase from pre-industrial times.
Find out more about what causes climate change.
3. Extreme Weather is Becoming More Common and Severe
Climate change is making heatwaves, floods, droughts and storms more frequent and intense. In 2024, extreme weather events disrupted schooling for 242 million students across 85 countries. Record-breaking floods devastated communities from Brazil to Bangladesh, while unprecedented heatwaves affected millions across multiple continents. Research shows that of 16 major flood events studied in 2024, 15 were amplified by climate change.
4. Sea Levels are Rising Faster Than Expected
Global sea level rose by 0.59 centimeters in 2024 - higher than the expected rate of 0.43 centimeters. Since 1993, sea levels have risen 10 centimeters (4 inches), and the rate of rise has more than doubled. This acceleration threatens coastal communities worldwide, with 1 billion people currently impacted by rising seas.
5. Glaciers and Ice Sheets are Melting at Record Rates
The Greenland ice sheet lost 105 billion tonnes of ice between September 2024 and August 2025 - the 29th consecutive year of ice loss. Globally, glaciers lost more ice in 2024 than any year on record. The Greenland ice sheet is losing approximately 9 billion litres of ice per hour, contributing significantly to sea level rise.
6. Wildlife and Ecosystems are Under Threat
Climate change is disrupting ecosystems worldwide. Rising temperatures force animals to migrate to cooler areas or face extinction. Coral reefs are dying as oceans warm and acidify. The Amazon rainforest and Pantanal Wetland experienced severe droughts and wildfires in 2024, leading to massive biodiversity loss. Changing seasons affect breeding and migration patterns, while extreme weather destroys habitats that took centuries to develop.
7. Food and Water Security are at Risk
Climate change threatens the foundations of food production. Changing rainfall patterns, increased droughts and extreme heat are reducing crop yields in many regions. According to the WHO, droughts and heatwaves were associated with an additional 124 million people facing moderate or severe food insecurity in 2023. Water scarcity is intensifying as glaciers that provide fresh water melt away and rainfall patterns become more unpredictable.
8. Human Health is Being Impacted Now
The average person was exposed to 16 days of dangerous heat in 2024 that wouldn't have occurred without climate change. For infants and older adults, that figure climbs to over 20 heatwave days - a fourfold increase over the past 20 years. Air pollution, waterborne diseases, malnutrition and mental health impacts from climate disasters are all increasing. Heat is arguably the deadliest extreme weather event, with thousands of deaths reported annually and many more unreported.
9. Children and Vulnerable Communities Suffer Most
According to our Generation Hope report, 774 million children worldwide are both living in poverty and at high risk of climate-related disasters. Children who have done the least to cause climate change are suffering its worst impacts. The effects are not evenly distributed - 88% of the global health burden associated with climate change is borne by children under five, predominantly in low-income countries.
Learn more about how climate change affects children.
10. Solutions Exist and Action Matters
Despite the serious challenges, effective solutions are being implemented. In 2024, renewables accounted for 51% of UK electricity generation - surpassing fossil fuels for the first time. Globally, renewable energy capacity grew by a record-breaking 15.1%, with 585 GW of new clean power added. The technology and knowledge to tackle climate change exist. What's needed is the political will to act with the urgency this crisis demands.
Learn more about the solutions to climate change.
Fiona, 18, next to her home in a community affected by rising sea levels in Malaita Province, the Solomon Islands.
The Major Effects of Climate Change
These facts reveal several major effects of climate change that are already transforming our world. Understanding these effects helps us grasp the scale of the challenge and the urgent need for action.
Rising Global Temperatures
The planet has warmed by approximately 1.3°C since pre-industrial times, with warming accelerating in recent decades. This might sound small, but even slight temperature increases trigger dramatic shifts across Earth's systems. The warming isn't uniform - some regions, particularly the Arctic, are heating much faster than the global average. Arctic temperatures in 2024 were the second-warmest in the 125-year record.
Higher temperatures create cascading effects. They accelerate glacier melt, intensify droughts, increase wildfire risk and stress ecosystems unable to adapt quickly enough. Urban areas face particular challenges, with heat islands making cities several degrees warmer than surrounding areas. Night-time temperatures are rising faster than daytime temperatures, reducing the relief that cooler evenings once provided.
More Extreme Weather Events
Climate change is fundamentally altering weather patterns, making extreme events more frequent and severe. Heatwaves are lasting longer and reaching higher temperatures. Climate Central's analysis found that carbon pollution made 89% of record high daily temperatures set across 247 major US cities in 2025 more likely.
Rainfall patterns are changing dramatically. Warmer air holds more moisture, leading to heavier downpours when it rains. "Hydroclimate whiplash" - swinging between extreme wet and dry conditions - is becoming more common.
Tropical storms are growing more intense. While the total number of cyclones may not increase significantly, warmer ocean temperatures fuel rapid intensification.
Rising Sea Levels and Coastal Flooding
Sea levels are rising due to two main factors: thermal expansion of warming oceans and meltwater from glaciers and ice sheets. The rate of rise is accelerating alarmingly. What was once gradual change is now rapid transformation. Sea levels have risen about 21-24 centimeters since 1880, with over half that rise occurring since 1993.
In 2024, thermal expansion unexpectedly accounted for two-thirds of sea level rise - a flip from recent years when melting ice was the dominant contributor. This reflects the unprecedented ocean warming occurring as the climate system absorbs vast amounts of heat. High-tide flooding is now 300% to over 900% more frequent than it was 50 years ago in many coastal locations.
The consequences extend far beyond submerged land. Saltwater intrusion contaminates freshwater aquifers and agricultural land. Coastal erosion accelerates. Storm surges reach farther inland, causing more extensive damage. Low-lying island nations and coastal communities face existential threats. Even wealthy nations with resources to build defences face enormous costs and difficult decisions about which areas to protect and which to abandon.
Impacts on Food and Water Security
Climate change threatens the foundations of agriculture. Changing rainfall patterns make farming unpredictable. Droughts reduce crop yields and kill livestock. Floods destroy harvests. Rising temperatures stress crops and reduce nutritional content. Pests and diseases previously limited by cold winters now survive year-round and expand their range.
The impacts are already severe. In Africa, staple crop yields have declined by 30-50% in many regions due to climate stressors. It is projected that more than 582 million people will be chronically undernourished by 2030. Food price volatility increases as weather becomes less predictable, hitting the poorest families hardest.
Water security faces similar challenges. Glaciers that provide fresh water to billions of people are shrinking. Groundwater depletion accelerates as communities pump more water to compensate for unreliable rainfall. Extreme weather events - both floods and droughts - damage water infrastructure. Water quality deteriorates as warming temperatures promote harmful algal blooms and waterborne diseases.
Effects on Human Health
Climate change is fundamentally a health crisis. Heat-related illnesses and deaths are rising. The World Health Organization estimates that between 2030 and 2050, climate change could cause approximately 250,000 additional deaths per year from malnutrition, malaria, heat stress and diarrhoeal disease.
Air pollution worsens as climate change increases ground-level ozone and extends wildfire seasons.
Vector-borne diseases like malaria and dengue fever are expanding their range as warming temperatures allow disease-carrying mosquitoes to survive in previously inhospitable areas. Waterborne diseases increase as floods contaminate water supplies. Extreme weather events cause injuries and deaths directly while disrupting healthcare access. Mental health impacts are profound, particularly for those who have experienced climate disasters or live with chronic climate anxiety.
Economic and Social Consequences
The economic costs of climate change are staggering and accelerating. 2025 was one of the costliest years for climate disasters on record, with the top 10 climate-related disasters causing $120 billion in economic losses.
These headline figures underestimate the true costs. They typically capture insured losses and direct damage but miss wider economic disruption, lost productivity, healthcare costs, ecosystem damage and the impossible-to-quantify cost of lives lost and communities destroyed. Poor countries and communities bear disproportionate costs relative to their resources while having contributed least to causing climate change.
Climate change amplifies existing inequalities. It forces people from their homes - weather-related disasters led to 43.1 million child displacements between 2016 and 2021 alone. It deepens poverty as families lose livelihoods, homes and access to services.
How Save the Children Protects Children from Climate Change Effects
At Save the Children, we understand that climate change is fundamentally a children's rights crisis. The 2.4 billion children alive today will live with the consequences of climate change for their entire lives - yet they had no role in creating the problem.
We're working alongside communities worldwide to protect children from climate impacts right now while building long-term resilience. In 2024, we supported the construction of over 1,150 climate-resilient classrooms in nearly 230 schools in Mozambique - a country repeatedly devastated by cyclones. These classrooms protect children during extreme weather and ensure learning continues even when disaster strikes.
We're helping families adapt through programmes that combine immediate support with sustainable solutions. In drought-affected areas, we introduce solar-powered water systems that provide reliable clean water even when rainfall fails. We train families in climate-resilient agriculture so they can continue growing food despite changing weather patterns. We provide cash support that gives families flexibility to meet urgent needs while investing in their futures.
When disasters strike, we're there with emergency response - but we also focus on helping communities prepare before disaster hits. This includes establishing early warning systems, training community disaster response teams and ensuring schools and healthcare facilities can withstand extreme weather. Our approach recognizes that the children who have done the least to cause climate change deserve the strongest protection from its impacts.
We're also advocating for systemic change. We're amplifying children's voices in climate decision-making because they have the right to shape the future they'll inherit.
The facts are clear. The effects are real and intensifying. But solutions exist, and when we act together - with urgency, fairness and children at the center - we can still build a safer, more sustainable world for every child.
Frequently Asked Questions
Are the Effects of Climate Change Reversible?
Some effects of climate change are reversible if we act quickly and decisively. If greenhouse gas emissions are reduced rapidly, global temperatures will eventually stabilize and some impacts will lessen. Ecosystems can recover if given time and protection. Air quality improves quickly when pollution is reduced.
However, other effects are irreversible on human timescales. Ice sheet collapse and the resulting sea level rise will continue for centuries even if emissions stop today. Species that go extinct cannot be brought back. Some tipping points, once crossed, trigger self-reinforcing changes that continue regardless of human action. The sooner we act, the more we can prevent irreversible damage.
How Quickly are the Effects of Climate Change Happening?
The effects of climate change are accelerating. What scientists predicted would happen gradually over decades is occurring faster than expected. Sea level rise in 2024 exceeded predictions. Ice sheets are melting more rapidly than models forecast. Extreme weather events are intensifying at rates that outpace earlier projections.
Some changes happen suddenly. Heatwaves strike within days. Floods occur in hours. Wildfires spread rapidly. Other changes unfold more slowly but accelerate over time - glaciers that took millennia to form are disappearing within decades. The pace of change varies by location and impact type, but the overall trend is clear: climate change is happening faster than anticipated.
Why Do Some Areas Experience Climate Change Effects More Severely Than Others?
Geography, poverty and existing vulnerabilities determine how severely climate change affects different areas. Low-lying island nations face existential threats from sea level rise. Arctic regions warm two to three times faster than the global average. Regions dependent on glaciers for water face acute scarcity as ice disappears.
Poverty amplifies climate impacts. Wealthier communities can afford flood defences, air conditioning, crop insurance and evacuation. Poor communities lack these protections. Countries with weak infrastructure, limited healthcare and political instability struggle to respond effectively to climate disasters. Children in low-income countries are four times more likely to face climate disasters than those in wealthy nations.
Does Climate Change Increase Inequality?
Yes, climate change is a profound inequality crisis. Those who have contributed least to causing it - particularly in low-income countries and communities - face the worst impacts.
Within countries, climate change deepens existing inequalities. Disadvantaged communities typically live in areas most exposed to climate risks - floodplains, drought-prone regions, areas with poor infrastructure. They have fewer resources to prepare for or recover from disasters. Climate impacts push vulnerable families deeper into poverty through destroyed livelihoods, damaged homes and increased costs. As our Generation Hope report shows, 774 million children worldwide face both poverty and high climate risk - a devastating double burden.
