Thousands of the world's greatest scientists have joined together to declare that 'untold human suffering' is unavoidable without deep and lasting shifts in human activities.

An alliance of more than 11,000 scientists signed the paper which declared the climate emergency before providing a set of effective actions humans could take.

To limit the damage caused by humans' greenhouse gas emissions the paper calls for more control over the massively booming global population, currently increasing by over 200,000 people a day.

Adding that population control would have to be approached with methods that ensured social and economic justice in order to sustain a morally and ecologically sound world.

USDA Forest Service Tallac Hotshots capture the sun glowing in the distance as the Carr fire burns

The global group is led by William J. Ripple professor of ecology at Oregon State University and researcher Christopher Wolf.

Professor Ripple said: 'Despite 40 years of major global negotiations, we have continued to conduct business as usual and have failed to address this crisis.

'Climate change has arrived and is accelerating faster than many scientists expected.'

The paper pointed to six areas in which humanity should take immediate steps to slow down the effects of a warming planet.

Firstly reducing the consumption of energy and replacing fossil fuels with low-carbon renewables - leaving remaining stocks of fossil fuels in the ground.

William J. Ripple professor of ecology at Oregon State University

They detail how this can be encouraged by eliminating subsidies to fossil fuel companies and imposing carbon fees that are high enough to restrain the use of fossil fuels.

Secondly the paper called for the reduction of 'short-lived pollutants' such as methane, soot and hydroflourocarbons to be drastically cut - calculating that the reduction could see the short-term warming trend cut 50 per cent over the next few decades.

The paper also suggests ecosystems such as forests, grasslands and mangroves are protected in order for them to reach 'ecological potential' and act as carbon dioxide converters - a prevalent green house gas created by human activity.

Humans are encouraged to adopt a diet with fewer animal products by the researchers.

The dietary shift would significantly reduce emissions of methane and other greenhouse gases and free up agricultural lands for growing human food rather than livestock feed.

Reducing food waste is also stated as critical - the scientists say at least one-third of all food produced ends up as garbage, meaning unnecessary emissions were created in producing it.

Scientists call for a 'carbon free' economy, shifting goals away from the growth of gross domestic product and the pursuit of extreme wealth.

Flooding level shown against a speed limit sign in Finchfield, Iowa, US

Instead humans should realise their 'dependence on the biosphere' and put that first, curbing the exploitation of ecosystems, writes the paper.

Finally the paper states that the growing rate of human population needs to slow in order to sustain an ecologically sound world.

WHAT STEPS CAN WE TAKE TO LIMIT CLIMATE CHANGE? Steps detailed in the paper written by William J. Ripple professor of ecology at Oregon State University and researcher Christopher Wolf. 1) Replace fossil fuels with low-carbon renewables 2) Swiftly cut emissions of methane, soot, hydrofluorocarbons and other short-lived climate pollutants 3) Restore and protect ecosystems to allow them to naturally convert CO2 emissions 4) Shift world's diet to plant based and reduce food waste 5) Shift economic goals towards maintaining biosphere - not gaining wealth 6) Stabilise global human population Advertisement

They add that population control would have to be approached with methods that ensured social and economic justice.

The paper was published today in BioScience and held more than 11,000 scientist signatories from 153 countries.

In conclusion the paper states: 'Mitigating and adapting to climate change while honoring the diversity of humans entails major transformations in the ways our global society functions and interacts with natural ecosystems.

'We are encouraged by a recent surge of concern. Governmental bodies are making climate emergency declarations. Schoolchildren are striking. Ecocide lawsuits are proceeding in the courts. Grassroots citizen movements are demanding change, and many countries, states and provinces, cities, and businesses are responding.

'As an Alliance of World Scientists, we stand ready to assist decision makers in a just transition to a sustainable and equitable future.'

Graphs of vital signs in the paper illustrate several key climate-change indicators and factors over the last 40 years, since scientists from 50 nations met at the First World Climate Conference in Geneva in 1979.

In recent decades, multiple other global assemblies have agreed that urgent action is essential, but greenhouse gas emissions are still rapidly rising.

Other ominous signs from human activities include sustained increases in per-capita meat production, global tree cover loss and number of airline passengers.

There are also some encouraging signs - including decreases in global birth rates and decelerated forest loss in the Brazilian Amazon, and increases in wind and solar power - but even those measures are tinged with worry.

The decline in birth rates has slowed over the last 20 years, for example, and the pace of Amazon forest loss appears to be starting to increase again.

Professor Ripple added: 'Global surface temperature, ocean heat content, extreme weather and its costs, sea level, ocean acidity, and area burned in the United States are all rising.

'Globally, ice is rapidly disappearing as demonstrated by decreases in minimum summer Arctic sea ice, Greenland and Antarctic ice sheets, and glacier thickness. All of these rapid changes highlight the urgent need for action.'