The Earth is heating rapidly
- In a year, the Earth gains heat equal to 73 times the energy the USA uses in that period.
- Each second, the planet gains as much heat as was liberated by 4 Hiroshima bombs.
- Each second, the planet gains as much heat as a petrol car uses to drive between Melbourne and Brisbane 41.6 million times.
This page shows the calculations behind these numbers.
Where the absorbed heat has gone
The graph shows the accumulation of heat by the Earth between 1962 and 2008
- The light blue shows the heat accumulating in the oceans. (The oceans have absorbed over 90% of the heat.)
- The brown shows the heat accumulating in the land, atmosphere and ice.
- The slope of the wiggly dark-blue line shows the rate of heating.
Graph from Sceptical Science: 27 March 2014
Four Hiroshima bombs worth of heat per second
Scientists use a range of measurements including data from satellites and robotic floats to estimate the heat content of the oceans.
The rate of heat accumulation
Let’s consider how fast the Earth is gaining this heat. We need to use large numbers for this, so to be clear:
- Ten raised to the power of two = 10 x 10 = 10^2 = 100
- Ten raised to the power of 6 = 10^6 = 1,000,000.
The Earth is getting hotter at a rate of:
- 7,800,000,000,000,000,000,000 joule/year
- 7.8 x 10^21 joule / year
- 2.16 x 10^19 joule/day
- 2.5 x 10^14 joule/second
This is 73 times the US energy consumption.
The US Energy Information Administration (EIA: Energy Facts) says that in 2018 the US energy usage, including petrol, natural gas, coal, nuclear and renewables, was:
- 101.3 quadrillion British Thermal Units (Btu)
- 101.3 x 10^15 Btu (1 Btu = 1055.056 joule)
- 1.069 x 10^20 joule / year
The Earth is heating at a rate of
- 7.8 x 10^21 joule / year
- = 7.8 x 10^21 / (1.069 x 10^20) times faster than the USA is consuming energy.
- = 78 / 1.069 = 73 times faster than the US is consuming energy.
This is 4 Hiroshima bombs per second.
The energy released by the atomic bomb dropped on Hiroshima was 6.3 x 10^13 joules.
The Earth is accumulating heat at a rate of
- 2.5 x 10^14 joule/second
- = 2.5 x 10^14 / (6.3 x 10^13) Hiroshima bombs every second.
- = 25 / 6.3 = 4 Hiroshima bombs every second.
Car trips from Melbourne to Brisbane
In terms of the energy in the petrol needed to travel by car from Melbourne to Brisbane.
- The trip is 1,675 km.
- Say the car uses 11 litres of petrol per 100 kilometres
- This gives 184.25 litres of petrol per trip
- Say the petrol has 32.6 million-joule / litre
- This gives 6,007 million joules / trip
The Earth is accumulating heat at a rate of
- 2.5 x 10^14 joule/second
- = 2.5 x 10^14 / (6,007 x 10^3) times more than this road trip every second.
- = 41.6 million times more than this road trip every second.
Loaded September 2019. Adjusted 6 September 2026