Global warming is the long-term rise in Earth’s average surface temperature caused mainly by human emissions of greenhouse gases. Climate change is the broader result: shifts in temperature, rainfall, sea level, ice, oceans, ecosystems, and the frequency or intensity of some extremes. The scientific evidence is not based on one hot year or one weather event. It comes from many independent observations, including surface temperature records, satellites, ocean heat measurements, glacier and ice-sheet loss, sea-level rise, atmospheric chemistry, and the physical understanding of how greenhouse gases trap heat.
The World Meteorological Organization — State of the Global Climate 2025 reported in March 2026 that 2015–2025 were the eleven warmest years on record and that 2025 was the second or third warmest year, about 1.43°C above the 1850–1900 average. It also reported record ocean heat content in 2025 and an increasingly large imbalance between the energy Earth receives and the energy it loses to space. Those findings reinforce a trend already documented by NASA — Evidence for Climate Change and the IPCC — AR6 Synthesis Report.
Global Warming Is Mainly Driven by Human Greenhouse-Gas Emissions
The greenhouse effect is a natural process that keeps Earth warm enough for life, but human activity has strengthened it by increasing concentrations of carbon dioxide, methane, nitrous oxide, and other heat-trapping gases. Burning coal, Oil and gas, and other fossil fuels is the largest source of human carbon-dioxide emissions, while land-use change, agriculture, waste, industrial processes, and energy production also contribute. Carbon dioxide matters especially because large quantities remain in the climate system for a long time and accumulate when emissions exceed natural removal.
Methane is shorter-lived than carbon dioxide but traps much more heat per molecule over shorter time horizons, making reductions valuable for slowing near-term warming. The evidence that human activity is the dominant cause comes from more than correlation. Scientists observe the expected pattern of atmospheric warming and stratospheric cooling, measure the changing isotopic signature of carbon from fossil fuels, track the radiative effect of greenhouse gases, and compare climate models with and without human forcing. NASA — Causes of Climate Change summarizes this attribution evidence in accessible form.
Warming Is Visible in Oceans, Ice, and Sea Level
The ocean absorbs most of the excess heat trapped by greenhouse gases, so ocean heat content is one of the clearest measures of long-term climate change. WMO reported that 2025 reached the highest ocean heat content in the observational record and that the recent rate of warming is much faster than in earlier decades. Warmer oceans contribute to marine heatwaves, coral stress, changing ecosystems, and sea-level rise through thermal expansion as seawater warms.
Glaciers and ice sheets are also losing mass, and the long-term rate of global mean sea-level rise has increased since the satellite era began. Sea-level rise does not affect every coast equally because land movement, ocean circulation, tides, and storms shape local risk, but higher baseline sea level makes coastal flooding and storm surge more damaging. Loss of mountain glaciers also affects communities that depend on seasonal meltwater for agriculture, hydropower, and drinking supplies.
Climate Change Alters the Risk of Extreme Events
Climate change does not create every heatwave, drought, flood, wildfire, or tropical cyclone, but it can change the probability and severity of those events. Extreme heat becomes more likely in a warmer baseline climate. A warmer atmosphere can hold more water vapor, increasing the potential for intense rainfall in many regions. Drought risk depends on rainfall, soil moisture, evaporation, water use, and land management, while wildfire risk depends on vegetation, ignition, weather, and fuel dryness as well as climate.
Tropical cyclones are more complicated because total storm counts do not simply rise in proportion to temperature. Warmer oceans and a moister atmosphere can increase the rainfall and peak intensity of the strongest storms, while sea-level rise raises coastal flood risk when storms make landfall. This is why Climate risks should be evaluated by hazard, exposure, and vulnerability together rather than by assuming that warming produces the same outcome everywhere.
Food, Health, and Inequality Turn Physical Change Into Human Impact
A hotter and less predictable climate can affect crop yields, livestock, fisheries, water availability, labor productivity, and food prices. Agriculture is already adapted to local seasons and temperature ranges, so rapid change can create stress even when some regions temporarily benefit from longer growing seasons. Heat also increases health risks directly, particularly for older adults, outdoor workers, infants, and people with cardiovascular or respiratory disease. Air pollution, wildfire smoke, infectious-disease ecology, and food insecurity can add further health burdens.
Impacts are unequal because people have very different levels of exposure and ability to adapt. A wealthy city can invest in cooling centers, flood defenses, resilient power systems, and insurance, while a low-income community may face the same hazard with fewer resources and more fragile infrastructure. Climate policy therefore involves both reducing future warming and managing unavoidable risks. Adaptation without mitigation eventually becomes harder as warming increases, while mitigation without adaptation leaves communities exposed to changes that are already occurring.
Mitigation Requires a Portfolio of Solutions
Reducing global warming requires bringing net greenhouse-gas emissions down, especially carbon dioxide from energy, transport, buildings, industry, and land use. Renewable electricity, efficiency, electrification, grid expansion, storage, methane control, low-carbon fuels, nuclear energy, and changes in land management can all contribute depending on local conditions. wind power is one important option, but no single technology can replace an entire energy system by itself.
Carbon capture may be useful for some industrial processes or residual emissions, but it should be evaluated alongside cost, energy use, storage integrity, and alternatives. Individual choices can reduce emissions and influence markets, yet infrastructure and policy determine many of the options available to households. The most effective climate strategy is therefore systemic: cleaner energy, efficient buildings and transport, industrial innovation, resilient infrastructure, land protection, and incentives that make low-emission choices practical at scale.
Conclusion
Global warming in 2026 is a measured physical reality, not a projection that might begin in the distant future. Human greenhouse-gas emissions are the dominant cause, and the evidence appears consistently across temperatures, oceans, ice, sea level, and atmospheric observations. The fact that 2025 was slightly cooler than 2024 in some datasets does not reverse the long-term trend; it still ranked among the warmest years ever measured. What happens next depends strongly on cumulative emissions. Some additional impacts are unavoidable, but the severity of future warming, sea-level rise, ecosystem loss, and extreme-weather risk can still be reduced through faster mitigation combined with practical adaptation.