Australian climate scientists have established the clearest evidence yet of the dramatic fingerprint humans have had on the climate.

Key points: Carbon dioxide, methane and nitrous oxide at highest levels ever over last 800,000 years

Carbon dioxide, methane and nitrous oxide at highest levels ever over last 800,000 years Levels rose significantly around the Industrial Revolution, then again in 1950s

Levels rose significantly around the Industrial Revolution, then again in 1950s Database shows gradual decline in some ozone-depleting gasses, such as CFSs

The researchers created a comprehensive worldwide database that charts 43 greenhouse gases over 2,000 years.

It shows how carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) are at higher levels than they have ever been at any time over the last 800,000 years, according to the ice core records going back that far.

The lead author of the new database, Malte Meinhausen, from the Australian-German Climate and Energy College at the University of Melbourne, said the research told scientists about the "concerning picture that we know".

"But now in more details and more colour — which is that greenhouse gases are rising relentlessly," he said.

"Over the last 2,000 years they have been very quiet, bobbing along at some natural level.

"But since the Industrial Revolution [around 1750] and particularly since 1950, they have been on the rise — that's what caused global warming and they have not stopped since."

Dr Meinhausen said the research had been compiled over decades by scientists to measure greenhouse gas concentrations in the atmosphere.

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"That research does the last step and compiles it all to the most complete data set that we have so far of 43 greenhouse gases," he said.

The data was based on contemporary and archived air samples taken from weather stations around the world.

For the older samples, scientists collected air that was trapped in bubbles in ice cores and compacted snow (firn) at the North and South Poles.

The data will now be used to create the climate models that will inform the Intergovernmental Panel on Climate Change's next assessment report, due in 2021.

It will allow scientists to do even more robust modelling of how climate change is effecting things like temperatures, weather patterns, sea level rise, and ice melting.

Dr Meinhausen said the key thing was to show how dramatic the human fingerprint on the climate had been.

"If we look at the whole 800,000 years of this Earth's history, we never had such big greenhouse gas concentrations — of CO2, of methane, and of a lot of other gases," he said.

"So we are doing an immense experiment with the planet and we are seeing the effects right now."

The research will be published today in the journal Geoscientific Model Development.

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What are these gases?

The three gases, CO2, CH2 and N2O, are well known as being among the principal causes of human-induced climate change.

While those gases would be found in the atmosphere even in the absence of human activity, the rise in their concentrations is due to human activities like burning fossil fuels, deforestation and agriculture.

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Some of the 43 gases included in the database are among the so-called synthetic greenhouse gases, such as dichlorodifluoromethane (CFC-12) and trichlorofluoromethane (CFC-11).

Whilst chlorofluorocarbons (CFCs) were phased out in the Montreal Protocol of the late 1980s, CFC-12 and CFC-11 are still the third and fifth-most important greenhouse gases in terms of overall contribution to global warming.

CFCs were predominantly emitted by humans in the forms of aerosol spray propellants, refrigerants, fire-extinguishing agents and in the production of semiconductors.

The database showed a gradual decline in these ozone-depleting gases including CFC-12 and CFC-14.

"In these records you see that some gases have changed in concentration, they've been reduced in concentration as a result of global protocols," David Etheridge said, co-author of the report from the CSIRO.

"So that gives everybody some hope that similar sort of actions can be taken to mitigate and reduce the other greenhouse gas concentrations."

Dr Etheridge said although gases like CO2, CH2 and N2O appeared quite diluted in the samples, that did not lessen their effect.

"They're at parts per million or less in the atmosphere, some are parts per trillion — but they're very powerful agents," he said.

"In total they comprise only about 0.05 per cent of the atmosphere.

"But as you know that's potentially quite a large amount — if you're looking for example at your blood alcohol level when you need to drive a car.

"So very dilute compounds can have a big effect."