Climate scenarios
The table shows GLOBAL average surface warming in 2081–2100 relative to 1850–1900, assessed in IPCC AR6. These are total changes since the pre-industrial baseline, not extra warming from 2026 or temperatures for a particular country or town. Each range is conditional on its emissions pathway. These three illustrative pathways are not assigned probabilities and do not cover every possible outcome.
| Emissions pathway | Averaging period | Best estimate | Very likely range |
|---|---|---|---|
| Low emissions · SSP1-2.6 | 2081–2100 | +1.8°C | +1.3 to +2.4°C |
| Intermediate emissions · SSP2-4.5 | 2081–2100 | +2.7°C | +2.1 to +3.5°C |
| Very high emissions · SSP5-8.5 | 2081–2100 | +4.4°C | +3.3 to +5.7°C |
From 2026: the next 25 years
Use this horizon to consider buildings, drainage, heat exposure and water resources. Natural variability still produces cold winters and wet or dry summers within a warming climate. Compare several models and decades; one simulated year cannot establish the conditions a household or community will face. Historical monthly averages in our calendar describe a past reference period, not these future projections.
2041–2060: compare regional changes
Differences between emissions pathways become increasingly important around mid-century. Regional assessments add detail about seasons, elevation and coastline that a global average cannot supply. A wetter annual climate can still include drought, and a drier season can still contain an intense downpour. These assessment windows overlap the near-term horizon; they are not separate daily forecasts.
2081–2100: understand the scenario table
The table summarises twenty-year global averages, with a best estimate and a very likely uncertainty range. A value is neither an annual maximum nor a local forecast. Lower emissions limit long-term warming; the very high pathway illustrates a substantially warmer outcome. Do not use a global temperature change as a uniform addition to every local day.
2101–2126: beyond the temperature table
The table stops at 2100. We do not extend its values in a straight line to 2126. Global mean sea level continues rising over centuries as oceans and land ice adjust. Conditions at an individual coast also depend on regional ocean changes, land movement and exposure. A global mean does not locate future flooding at an address.
How the regional outlook differs
Across the United States and Canada, warming increases heat-related risks, while changes in water, snow and drought differ by region. The southwestern United States faces greater aridity; Canadian assessments identify increasing heavy-rain risks and changing snowmelt. A broad North American trend should not be transferred unchanged to Alaska, Hawaii, the Arctic or a particular mountain catchment.
For the United Kingdom and Ireland, national assessments point towards warmer conditions, generally wetter winters and drier summers. These are long-term tendencies, not a promise about every season. Heavier rainfall episodes can still occur during a period with less total rain, with drainage and terrain shaping the consequences.
Australia faces further warming, more intense short-duration heavy rain and increased dangerous fire weather in many regions, with important regional differences. New Zealand projections also show warming and changing rainfall extremes; mountain terrain and season influence local outcomes. Compare national climate services using the same scenario, baseline and averaging period before applying a number to a local decision.
Questions about the weather calendar
Can you forecast the weather 100 years ahead?
No. Climate projections describe changing averages, variability and extremes under stated assumptions. They cannot predict the temperature or rainfall on a particular day a century from now.
Is the middle scenario the most likely future?
Not simply because it is the middle row. The pathways depend on future emissions and societal choices. Their uncertainty ranges describe climate outcomes within each pathway, not the chance that society follows that pathway.