Climate change is visible in the latest measurements of temperature, greenhouse gases, oceans, sea level, extreme weather, and emissions. The figures below describe 2023 and 2024 observations, alongside the forward-looking reductions identified by the United Nations Environment Programme (UNEP).
Contents
- Global temperature records
- Oceans, ice, snow, and sea level
- Greenhouse gas concentrations
- Energy and global emissions
- Where emissions come from
- Extreme weather and U.S. impacts
- The emissions gap to 1.5°C
Global temperature records
The World Meteorological Organization (WMO) reported that 2024 was the warmest year on record, at 1.55 ± 0.13°C above the 1850–1900 average. It was likely the first calendar year to exceed 1.5°C above that pre-industrial reference period. WMO also reported that the 10 years from 2015 through 2024 were the 10 warmest years ever recorded. These are calendar-year measurements; they do not by themselves establish that the longer-term Paris Agreement temperature threshold has been permanently exceeded.
NOAA’s global temperature record, which extends back to 1850, also ranked 2024 as the warmest year. NOAA measured the year at 2.32°F (1.29°C) above the 20th-century average and 2.63°F (1.46°C) above the 1850–1900 pre-industrial average. The 2024 global temperature was 0.18°F (0.10°C) higher than 2023.
Taken together, the WMO and NOAA figures use different reference periods and measurement frameworks, so their values should be compared with care. They point in the same direction: recent global temperatures are at the highest levels in the records cited here.
Oceans, ice, snow, and sea level
NOAA reported record-high upper-ocean heat content in 2024. The oceans store about 90% of the excess heat in the Earth system, making ocean heat content an important measure of the climate system’s accumulated energy.
Global mean sea level was about 4.0 inches (105.8 mm) above the 1993 average in 2024, according to NOAA’s BAMS State of the Climate 2024. That was a record high for the 13th consecutive year. Since 2005, warming oceans contributed an average of 1.5 ± 0.3 mm per year to sea-level rise, while melting ice sheets and glaciers contributed an average of 2.1 ± 0.4 mm per year.
The cryosphere also showed large seasonal variation in 2024. Antarctic sea-ice extent was the second lowest on record in February and again the second lowest on record in September, according to NOAA’s Assessing the Global Climate in 2024. Northern Hemisphere snow cover averaged 9.2 million square miles across the year. It reached 18.1 million square miles in January and fell to 1.0 million square miles in August.
| Indicator | 2024 measurement | Reference or timing |
|---|---|---|
| Global mean sea level | 4.0 inches (105.8 mm) above average | Compared with 1993 average |
| Ocean contribution to sea-level rise | 1.5 ± 0.3 mm per year | Average since 2005 |
| Ice-sheet and glacier contribution | 2.1 ± 0.4 mm per year | Average since 2005 |
| Northern Hemisphere snow cover | 18.1 million square miles | January 2024 |
| Northern Hemisphere snow cover | 1.0 million square miles | August 2024 |
Greenhouse gas concentrations
NOAA’s BAMS State of the Climate 2024 reported global carbon dioxide at 422.8 ± 0.1 parts per million (ppm) in 2024. That level was 52% above the pre-industrial level of about 278 ppm, and global mean CO2 grew by 3.4 ppm from 2023 to 2024. For context, the annual CO2 growth rate was 0.6 ± 0.1 ppm per year in the early 1960s and averaged 2.4 ppm per year during 2011–2020.
WMO’s Greenhouse Gas Bulletin No. 21 reported a 2024 CO2 concentration of 423.9 ± 0.2 ppm, along with methane at 1,942 ± 2 parts per billion (ppb) and nitrous oxide at 338.0 ± 0.1 ppb. The CO2 values differ because the organizations’ reported measurement products and methods are not identical; they should be retained as separate source figures rather than treated as one combined estimate.
NOAA’s Annual Greenhouse Gas Index (AGGI) reached 1.54 in 2024. NOAA said this represented a 54% increase in effective radiative forcing since 1990 and 3.54 watts per square meter (W/m²) of additional heat retained by Earth’s climate system relative to pre-industrial times. Carbon dioxide contributed 2.33 W/m², or 66% of the total forcing, while methane contributed 0.57 W/m², or 16%.
Energy and global emissions
The International Energy Agency (IEA) estimated energy-related CO2 emissions at 37.8 gigatonnes (Gt) in 2024. It reported that these emissions rose by 0.8% during the year. Fuel-combustion emissions increased by about 1%, or 357 megatonnes (Mt) of CO2, while industrial-process emissions fell by 2.3%, or 62 Mt of CO2.
Natural-gas emissions rose by around 2.5%, an increase of 180 Mt of CO2, according to the IEA. The agency also reported that global gross domestic product grew by 3.2% in 2024 while emissions growth remained below GDP growth. That comparison describes the relationship between the two growth rates; it does not mean total energy-related emissions declined.
UNEP’s Emissions Gap Report 2024 reported a broader measure: global greenhouse-gas emissions reached a record 57.1 GtCO2e in 2023, up 1.3% from 2022. The IEA’s 37.8 Gt figure is energy-related CO2 for 2024, while UNEP’s 57.1 GtCO2e includes greenhouse gases and sectors in a different accounting year and unit. These figures are not interchangeable totals.
Where emissions come from
UNEP reported the following sector emissions for 2023:
- The power sector emitted 15.1 GtCO2e.
- Transport emitted 8.4 GtCO2e.
- Agriculture emitted 6.5 GtCO2e.
- Industry emitted 6.5 GtCO2e.
International aviation emissions grew by 19.5% in 2023, according to the same UNEP report. The sector figures describe global greenhouse-gas emissions in 2023 and use CO2-equivalent accounting. They should not be added to the IEA’s 2024 energy-related CO2 estimate.
The distribution of emissions shows why climate action spans electricity, transport, food and land systems, industrial production, and aviation. The numbers also show why progress in one part of the economy does not automatically offset rising emissions elsewhere.
Extreme weather and U.S. impacts
NOAA counted 85 named tropical storms across the globe in 2024. The North Atlantic season produced 18 named tropical cyclones and five landfalling hurricanes. NOAA’s U.S. climate assessment likewise reported 18 named tropical cyclones in the 2024 Atlantic basin.
Antarctic sea ice was not the only cryosphere indicator at a low level, and the year also brought costly U.S. weather and climate disasters. NOAA counted 27 individual U.S. billion-dollar disasters in 2024. They caused at least 568 direct or indirect fatalities and approximately $182.7 billion in damage. NOAA ranked 2024 as the fourth-costliest U.S. year on record for billion-dollar disasters.
The 27 disasters included 17 severe storms, five tropical cyclones, two winter storms, one flooding event, one drought or heat wave, and one wildfire event, according to NOAA’s Assessing the U.S. Climate in 2024.
Since 1980, the United States has had 403 weather and climate disasters with at least $1 billion in damages. The cumulative cost of those disasters exceeded $2.915 trillion. These totals are NOAA’s disaster-accounting figures and include direct and indirect impacts as specified by the source; they are not a complete estimate of every climate-related loss.
NOAA also confirmed at least 1,735 U.S. tornadoes in 2024. That was the second-highest annual count on record, behind 2004, when 1,817 tornadoes were recorded.
The contiguous United States had an average annual temperature of 55.5°F in 2024, which was 3.5°F above average. Annual precipitation was 31.58 inches, or 1.66 inches above average. These are U.S. measurements and should not be generalized to global conditions.
The emissions gap to 1.5°C
UNEP identified the scale of near-term reductions needed to remain on pathways associated with the temperature goals. Annual emissions must fall 42% by 2030 and 57% by 2035 to stay on track for 1.5°C, according to the Emissions Gap Report 2024.
UNEP estimated that current unconditional nationally determined contributions (NDCs) leave a 2030 gap of 14 GtCO2e for a pathway below 2°C. For a 1.5°C pathway, the estimated 2030 gap is 22 GtCO2e. These are estimates of the difference between current commitments and modeled pathway requirements, not forecasts of a measured future emissions total.
The contrast is clear: 2023 global greenhouse-gas emissions reached 57.1 GtCO2e, energy-related CO2 emissions rose to an estimated 37.8 Gt in 2024, and greenhouse-gas concentrations continued to rise. At the same time, UNEP’s pathway estimates quantify the reductions required by 2030 and 2035. For climate action guides, those dates and percentages provide a practical scale for judging whether proposed measures address the size of the challenge.