Global Surface Temperature Increase
1.2°C
Earth has warmed 1.2°C since pre-industrial levels (1850–1900). The rate of warming since 1970 is unprecedented in at least 2,000 years.
Earth has warmed 1.2°C since pre-industrial levels (1850–1900). The rate of warming since 1970 is unprecedented in at least 2,000 years.
Global warming refers to the long-term heating of Earth's climate system observed since the pre-industrial period due to human activities — primarily the burning of fossil fuels, which increases heat-trapping greenhouse gas levels in the atmosphere.
The planet's average surface temperature has risen about 1.2°C since the late 19th century, a change driven largely by increased carbon dioxide emissions and other human activities. Most of the warming occurred in the past 40 years, with the seven most recent years being the warmest on record.
The evidence is overwhelming: 97% of actively publishing climate scientists agree that climate-warming trends over the past century are extremely likely due to human activities. This is not a debate — it is a measured, observed, and independently verified reality.
How greenhouse gases trap heat, the carbon cycle, climate feedback loops, and why 1.2°C matters more than it sounds.
Explore →Sea level rise, extreme weather, ecosystem collapse, food security, human displacement — what's already happening and what's projected.
Explore →Renewable energy, carbon pricing, reforestation, technological innovation, and the policy pathways to net zero.
Explore →The fundamental physics has been understood since the 19th century. Greenhouse gases trap infrared radiation — more gas means more heat retained. The rest is measurement, modeling, and verification.
Solar radiation passes through the atmosphere and warms Earth's surface. The surface radiates heat back as infrared. Greenhouse gases (CO₂, CH₄, N₂O, water vapor) absorb and re-radiate this infrared energy, trapping heat — exactly as a greenhouse does. Without this natural effect, Earth's average temperature would be about −18°C instead of +15°C.
Physics · 1824Human activities have increased atmospheric CO₂ by 50% since 1750 — from ~280 ppm to ~421 ppm. This additional CO₂ amplifies the natural greenhouse effect, trapping more heat. Methane (CH₄) has more than doubled. The result: ~3.2 W/m² of additional radiative forcing — equivalent to adding the energy of ~800,000 Hiroshima bombs per day to the climate system.
Anthropogenic · MeasuredWarming triggers self-reinforcing cycles: melting ice reduces albedo (reflectivity), causing more absorption. Thawing permafrost releases methane. Warmer oceans absorb less CO₂. Forest fires release stored carbon. These feedbacks mean that initial warming can cascade — a critical reason why every fraction of a degree matters.
Systems · Amplifying"To limit warming to 1.5°C with 50% probability, the remaining carbon budget is approximately 275 GtCO₂. At current emission rates (~40 GtCO₂/yr), this budget is exhausted in under 7 years."
Direct Measurements: Thermometer records since 1850, satellite measurements since 1979, Argo ocean float network since 2000.
Proxy Data: Ice cores (800,000 years of trapped air bubbles), tree rings, coral skeletons, ocean sediments, speleothems — all independently cross-validated.
Climate Models: General Circulation Models (GCMs) that solve physical equations for atmosphere, ocean, land, and ice. When run without human emissions, they show no warming. With emissions, they reproduce observed temperatures with remarkable accuracy.
CO₂ — Carbon Dioxide: Primary driver. Lifetime: centuries to millennia. Current: 421 ppm (+50%). Sources: fossil fuels, deforestation, cement.
CH₄ — Methane: 28× more potent than CO₂ over 100 years (84× over 20). Lifetime: ~12 years. Sources: agriculture, fossil fuel extraction, landfills.
N₂O — Nitrous Oxide: 265× more potent than CO₂. Lifetime: ~121 years. Sources: agriculture (fertilizers), industrial processes, biomass burning.
The effects of global warming are not a future problem — they are measurable, observable, and accelerating today. Here is what the data shows across five critical dimensions.
Global mean sea level has risen ~20 cm since 1901, with the rate accelerating from 1.4 mm/yr (1901-1990) to 3.6 mm/yr (2006-2024). Thermal expansion + ice melt.
The number of weather-related disasters has increased five-fold over the past 50 years, driven by climate change, according to the World Meteorological Organization.
IPBES reports that ~1 million animal and plant species face extinction, many within decades — climate change is the third most significant driver after habitat loss and exploitation.
By 2100, sea levels are projected to rise 0.3–1.1 m under low-emission scenarios and 0.6–2.0 m under high-emission scenarios. Over 600 million people live in coastal zones less than 10 m above sea level. Cities at acute risk include Jakarta, Mumbai, Shanghai, Miami, and Bangkok. Saltwater intrusion threatens freshwater supplies and agriculture in river deltas from the Mekong to the Nile.
A warmer atmosphere holds more water vapor (~7% per 1°C), intensifying precipitation and flooding. Simultaneously, warming increases evaporation, amplifying drought severity and wildfire risk. Hurricane intensity (Category 4-5) has increased. Heat waves that occurred once per decade in the 1850-1900 period now occur ~2.8 times per decade — and at 1.5°C warming, 4.1 times.
Coral reefs: 70-90% projected to decline at 1.5°C warming; >99% at 2°C. Arctic sea ice declining at 13% per decade. Species range shifts poleward at ~17 km per decade on land and ~72 km per decade in the ocean. Phenological mismatches: spring events advancing 2-3 days per decade, disrupting food webs. Amazon rainforest approaching a tipping point where it transitions to savanna.
Food Security: Each 1°C of warming reduces global wheat yields ~6%, rice ~3%, maize ~7%. Health: Heat-related mortality rising; vector-borne diseases (malaria, dengue) expanding range. Displacement: World Bank projects 216 million people could be internally displaced by 2050 due to climate impacts. Economic Cost: Estimated $178 trillion in cumulative damages by 2070 under business-as-usual (Deloitte).
The technology exists. The economics increasingly favor action. What's needed is deployment velocity, policy alignment, and global coordination at a scale unprecedented in human history.
Solar PV costs have fallen 89% since 2010. Onshore wind down 70%. Renewables are now the cheapest source of new electricity in countries representing >90% of global GDP. In 2024, renewables accounted for ~30% of global electricity generation — up from 19% in 2000. The IEA projects renewables will surpass coal as the largest electricity source by 2025.
Energy73 carbon pricing initiatives now cover ~23% of global emissions. The EU Emissions Trading System (ETS) covers ~40% of EU emissions, with carbon prices reaching €100/tonne in 2024. Studies show carbon pricing is the single most efficient policy instrument — it internalizes the externality and lets markets find the cheapest abatement path.
PolicyReforestation, afforestation, wetland restoration, and soil carbon sequestration could provide ~30% of the mitigation needed by 2030. The Bonn Challenge aims to restore 350 million hectares of degraded land by 2030. Mangrove restoration protects coasts AND sequesters carbon at 4-5× the rate of terrestrial forests.
EcosystemTransport (~15% of emissions): EV sales reached 18% of global car sales in 2024, up from 4% in 2020. Heat pumps outsold gas furnaces in the US for the first time in 2023. Industrial electrification, green hydrogen for hard-to-abate sectors (steel, cement, chemicals), and building efficiency retrofits represent massive mitigation wedges.
All IPCC pathways that limit warming to 1.5°C require carbon dioxide removal (CDR). Direct Air Capture (DAC): Climeworks' Orca plant captures 4,000 tCO₂/yr; scaled facilities targeting megaton scale by 2030. Enhanced weathering, biochar, ocean alkalinity enhancement, and BECCS (bioenergy with CCS) are the portfolio. Current global CDR: ~2 GtCO₂/yr (mostly forests). Required by 2050: 5-10 GtCO₂/yr.
Signed by 154 nations at the Rio Earth Summit. Established the principle of "common but differentiated responsibilities" and set the framework for all subsequent climate treaties.
First legally binding emissions reduction targets for developed nations. Covered ~5% reduction from 1990 levels by 2008-2012. Limited by US non-ratification and exclusion of developing nations from binding targets.
Landmark accord signed by 196 parties. Goal: limit warming to "well below 2°C," pursuing 1.5°C. Nationally Determined Contributions (NDCs) with five-year ratchet mechanism. Universally ratified by 2017.
First explicit mention of fossil fuels in a COP decision. Agreement to "phase down" unabated coal power and "phase out" inefficient fossil fuel subsidies. Completion of the Paris Rulebook.
First Global Stocktake concluded with a call to "transition away from fossil fuels." Agreement to triple renewable energy capacity and double energy efficiency improvement rates by 2030.
"The world is not on track to limit global warming to 1.5°C. Current policies project ~2.7°C of warming by 2100. But every tenth of a degree matters — and the difference between 2.0°C and 2.5°C is measured in lives, ecosystems, and economic costs of trillions of dollars."
Interactive charts built from NASA GISS, NOAA, Mauna Loa Observatory, and IPCC datasets. Hover, explore, and understand the evidence directly.