Greenhouse gases will need to be severely reduced by the year 2050 in order to limit damage done by global warming, a new draft report from the United Nations (UN) will announce.

Emissions of gases which lead to rising temperatures will need to be reduced by between 40 and 70 percent below 2010 levels in order to avoid the worst possible effects of the heating, according to researchers taking part in the report.

Reuters news service first obtained copies of the study, which examines three climate reports published over the last year by the United Nations. Although this new meta-study does not contain new research, the report does clarify many conclusions of the original trio of investigations.

This investigation was conducted by the Intergovernmental Panel on Climate Change (IPCC). In it, they stated that rising global temperatures are already causing damage on all seven continents. This comes in the form of greater temperature extremes, damage to crops, and melting ice sheets in Greenland and at the poles.

The UN previously set a goal of limiting global temperature rise to just 3.6 degrees Fahrenheit above pre-industrial levels. Since the start of the Industrial Revolution, global temperatures have risen by an average of 1.44 degrees Fahrenheit. Nearly 200 nations from around the world are scheduled to sign an agreement to limit global emissions of greenhouse gases. The signing ceremony will take place in Paris near the end of 2015.

Renewable energy sources, such as solar and wind power, would need to be doubled or tripled over today's usage in order to meet this goal. Nuclear power, with its low contribution to greenhouse gas emissions, would also need to meet similar increases in production. This would have the effect of creating additional nuclear waste, as plants would take on providing additional load.

The meta-study stated there is at least on a 95 percent chance that human activity is to blame for rising global temperatures.

"Human influence on the climate system is clear, and is estimated to have been the dominant cause of the warming observed since 1950," the draft Synthesis Report states.

The draft report, obtained by the news service, was completed on 21 April. Since that time, the document has been edited by researchers when they met between the end of June, and the beginning of July. The final draft of the meta-study will be provided to governments in August, and will be edited once more on 27 Oct., at a conference to be held in Copenhagen.