Earth is gaining energy.
That changes everything.
Every second, our planet absorbs more energy from the Sun than it radiates back to space. That difference — Earth's Energy Imbalance — is arguably the single most important number in climate science.
- Current EEI
- +1.8 W/m²
- Where it goes
- ~89%
- Trend
- ×2
CERES, 2015–2023 mean
Absorbed by the oceans
Doubled since ~2005
What is Earth's Energy Imbalance?
Earth is heated by sunlight and cooled by the infrared radiation it emits to space. When these two flows are unequal, energy accumulates in the climate system. That difference — measured in watts per square meter — is Earth's Energy Imbalance (EEI).
Energy flow — simplified
- Incoming solar radiation340 W/m²
- Reflected by clouds, ice & surface~100 W/m²
- Absorbed by land, ocean, atmosphere~240 W/m²
- Outgoing infrared radiation~238 W/m²
- Energy imbalance+1.8 W/m²
Incoming
~340 W/m²
Solar radiation reaching the top of the atmosphere, averaged over the planet.
Reflected + emitted
~338 W/m²
Reflected sunlight plus outgoing longwave (infrared) radiation.
Imbalance
+1.8 W/m²
A small residual — but sustained over decades it drives global warming.
Why the imbalance matters
A watt per square meter sounds trivial. Multiplied across Earth's surface and integrated over decades, it is equivalent to detonating several Hiroshima-scale bombs of energy every second, entirely absorbed by the climate system.
Ocean warming
~89% of the trapped heat is absorbed by the oceans.
Glacier & ice loss
Warmer oceans and air melt polar ice and mountain glaciers.
Sea-level rise
Thermal expansion + meltwater is raising oceans ~4 mm/yr.
Hotter atmosphere
Excess energy fuels heatwaves, drought and stronger storms.
Marine heatwaves
Ocean surface temperatures reach records almost every year.
Where the extra heat goes
Almost all of the energy Earth accumulates ends up in the oceans. That is why sea-surface and deep-ocean temperatures — not just air temperature — are the truest thermometer of climate change.
- Oceans89%
The oceans are the great heat sink of the planet.
- Land6%
Warming continents, soils and permafrost.
- Melting ice4%
Glaciers, sea ice and ice sheets.
- Atmosphere1%
The air we breathe holds only ~1% of the excess heat.
Source: von Schuckmann et al. (2023), Heat stored in the Earth system 1960–2020, Earth System Science Data.
Earth's Energy Imbalance is accelerating
Over the past two decades, EEI has roughly doubled — a pace faster than most climate models projected. Understanding why is now one of the most active questions in climate science.
Data: NASA CERES EBAF Ed4.2 (Loeb et al., 2021, updated). Annual global mean top-of-atmosphere net radiation, anchored to ocean heat content.
Greenhouse gases
CO₂ and methane concentrations continue to rise, reducing the outgoing longwave radiation Earth can emit to space.
Reduction in aerosol cooling
Cleaner shipping fuel (IMO 2020) and reduced industrial pollution have removed some of the reflective aerosols that previously masked warming.
Declining planetary reflectivity
Melting sea ice, reduced snow cover and darker land surfaces all reduce how much sunlight Earth reflects back to space.
Cloud feedbacks
Warming appears to be shifting cloud cover in ways that let more solar energy reach the surface — a positive feedback of growing concern.
Ocean response
Circulation and mixing changes redistribute heat and, in some regions, expose warmer sub-surface water to the atmosphere.
James Hansen — the man who saw it coming
For four decades, Dr James Hansen has argued that Earth's Energy Imbalance is the single most physically meaningful indicator of climate change. His recent work suggests warming is accelerating — and that we are, as he puts it, entering a new era.
Biography
Former director of the NASA Goddard Institute for Space Studies, Hansen first testified to the US Congress in 1988 that human-caused global warming had begun. He now directs the Climate Science, Awareness and Solutions program at Columbia University's Earth Institute.
Scientific contributions
- • Pioneered climate sensitivity analysis from paleoclimate records.
- • Championed EEI as the definitive test of the planet's energy state.
- • Warned early about ice-sheet instability and sea-level rise.
"Earth's Energy Imbalance is the most fundamental metric defining the status of Earth's climate. It measures how much more energy is being absorbed than emitted — and it is now larger than at any time in the modern record."Read Hansen's latest paper
How we measure Earth's Energy Imbalance
EEI is measured from two independent perspectives — from space, using satellites, and from within the ocean, using floats. Where the two agree, we know the number is real.
Step 1
CERES satellites
Continuously measure radiation entering and leaving Earth at the top of the atmosphere since 2000.
Step 2
Top-of-atmosphere flux
The difference between absorbed sunlight and outgoing infrared gives the net imbalance.
Step 3
Ocean heat content
Because ~89% of the excess energy ends up in the oceans, measuring OHC anchors EEI.
Step 4
Argo floats
A global array of ~3,900 autonomous floats profiles temperature and salinity to 2,000 m depth.
Step 5
Validation
Satellite and in-situ observations are compared, converging on ~+1 W/m² long-term average.
Earth's Energy Budget
Hover or tap each part of the diagram to understand what it does — and how they combine to produce the imbalance.
solar
Incoming solar radiation
340 W/m²
Sunlight reaching the top of the atmosphere, averaged over the whole planet, day and night.
Based on the global mean energy budget from Wild et al. (2019) and IPCC AR6 WG1 Ch.7 (2021).
Why Earth's reflectivity matters
Earth's Energy Imbalance is governed by two levers: how much infrared can leave the planet, and how much sunlight is absorbed rather than reflected. The first depends on greenhouse gases. The second depends on Earth's reflectivity — and that is where MEER's work sits.
Lever 1
Reducing outgoing infrared
Greenhouse gases absorb the infrared radiation Earth emits. Cutting emissions slows the rise of atmospheric CO₂, which — over decades — slows the reduction in outgoing radiation. This is the primary long-term solution.
Lever 2
Restoring reflectivity
Every square meter of bright surface reflects sunlight straight back to space. Restoring lost albedo — through reflective roofs, radiative cooling materials, protected snow and ice — represents a measurable, physically direct pathway toward reducing the imbalance.
Frequently asked questions
Short, careful answers to the questions people ask most about Earth's Energy Imbalance.
Because humans have rapidly changed the composition of the atmosphere. Higher greenhouse gas concentrations reduce the infrared radiation leaving Earth, while reflectivity changes and shifting cloud patterns modify how much sunlight is absorbed.
Water has an enormous heat capacity, and the oceans cover 71% of the planet. They quietly absorb about 89% of the excess energy trapped by the imbalance — which is why deep-ocean temperature is the most reliable indicator of climate change.
Rising greenhouse gases, declines in reflective aerosols, loss of sea ice and snow cover, and shifts in cloud cover all combine to push more energy into the system than leaves it.
Yes — briefly. Large eruptions inject sulfate aerosols into the stratosphere, temporarily reflecting sunlight and cooling the surface for a year or two. The long-term trend is unaffected.
El Niño redistributes heat from the ocean to the atmosphere, so surface temperatures rise even though total energy content changes little. It affects year-to-year noise, not the underlying imbalance.
NASA's CERES instruments measure the total radiation entering and leaving the top of the atmosphere. The difference — after careful calibration — is the imbalance. Results are anchored to independent measurements of ocean heat content.
Temperature can rise, fall or stall depending on where heat moves. But if EEI is positive, the total energy in the climate system is increasing. It is the ledger, not the thermometer.
Scientific references
Every figure on this page is drawn from peer-reviewed literature or authoritative observational datasets. Follow the links for the underlying data.
Global warming in the pipeline
Hansen et al., Oxford Open Climate Change (2023)
Satellite and Ocean Data Reveal Marked Increase in Earth's Heating Rate
Loeb et al., Geophysical Research Letters (2021)
Heat stored in the Earth system 1960–2020
von Schuckmann et al., Earth System Science Data (2023)
CERES EBAF Top-of-Atmosphere data product
NASA Langley Research Center
NASA GISS Surface Temperature Analysis (GISTEMP v4)
NASA Goddard Institute for Space Studies
NOAA Global Ocean Heat and Salt Content
NOAA National Centers for Environmental Information
IPCC AR6 WG1 — The Physical Science Basis
Intergovernmental Panel on Climate Change (2021)
The Argo Programme — global ocean observing array
Argo, an international program
Continue exploring
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Related glossary terms
- Radiative Cooling→
Heat loss from any object by emitting thermal infrared radiation.
- UHI→
The phenomenon where cities are noticeably hotter than the surrounding countryside.
- MRT→
The average temperature of every surface radiating heat toward a person.
- PDRC→
A material that stays cooler than the air even under direct sunlight by radiating heat to the cold sky.
- Thermal Emittance→
How efficiently a surface releases heat as infrared radiation.
- Adaptive Mitigation→
Interventions that adapt to warming today and reduce warming tomorrow.