Leaders of the G7 nations committed to take "urgent and concrete action" on climate change in 2015. Part of that action includes developing a new climate agreement during the Paris Climate Summit in early December that would limit global warming to less than 2 degrees Celsius, or 3.6 degrees Fahrenheit, above preindustrial conditions.

In a leaders' declaration issued at the end of the meeting in Krun, Germany on Monday, the G7 committed to taking strong steps to ensure that global warming remains under the 2-degree-Celsius benchmark established during previous rounds of international climate talks.

These steps include cutting greenhouse gas emissions by 40 to 70% by 2050, compared to 2010 levels, and decarbonizing their economies by the end of the century.

These goals are widely considered to be extremely ambitious given that global warming emissions have continued to rise in recent years, particularly in developing countries such as China and India.

“Today, for the first time ever, G7 leaders have rallied behind a long-term goal to decarbonize the global economy. This long-term decarbonization goal will make evident to corporations and financial markets that the most lucrative investments will stem from low-carbon technologies. This target must also be a key element of an ambitious international climate agreement," said Jennifer Morgan, who directs the climate change program for the World Resources Institute, an environmental think tank.

In the summit document, the G7 committed to forging "another legal instrument or an agreed outcome with legal force." This ambiguous wording recognizes the fact that a formal treaty that would need to be submitted to the U.S. Senate would be dead on arrival due to Republican opposition, so any agreement would need to have international legal force without needing to go to Congress.

The G7 calls for the Paris climate agreement, which would go into effect in 2020, to be "ambitious, robust, inclusive and reflects evolving national circumstances."

"We continue to make progress toward a strong climate agreement," President Obama said in a post-G7 press conference.

The supporters

The decarbonization goal is one supported by many small island states, Germany, and other countries in favor of taking major steps toward a clean energy economy that cuts emissions in line with what numerous scientific studies have recommended.

If achieved, the decarbonization target would mean that, by the year 2100, the group of seven major industrialized nations (the UK, Germany, U.S., Italy, Japan, France, Canada and the European Union) would no longer burn greenhouse gas-emitting fuels such as oil, coal and natural gas for energy. This would require a huge increase in the use of renewable energy technologies, like wind and solar power.

"....We emphasize that deep cuts in global greenhouse gas emissions are required with a decarbonization of the global economy over the course of this century," the leaders' declaration says.

Environmental groups greeted the news with optimism, but said the document was short on specifics.

“The G7 is sending a signal that the world must move away from fossil fuels, and investors should take notice,” said May Boeve, executive director of the environmental organization 350.org, in a statement. “If you’re still holding onto fossil fuel stocks, you’re betting on the past. As today’s announcement makes clear, the future belongs to renewables.”

World Bank Group President Jim Yong Kim also released a statement in support of the G7's declaration. Kim has made backing renewable energy rather than fossil fuels a priority during his tenure so far.

“The G7 leaders issued a powerful statement on climate change today, committing themselves to aggressive action to reduce greenhouse gas emissions and to lead the decarbonization of the global economy," he said.

The G7 leaders met in Bavaria at the same time as U.N. climate negotiators were slogging through the task of winnowing down a rough draft of the Paris climate agreement at a meeting in Bonn. That agreement, the G7 leaders stated, should include a process to track progress "towards achieving targets" and to ratchet up the emissions targets that each country makes over time.

The leaders' declaration states:

The agreement should enhance transparency and accountability including through binding rules at its core to track progress towards achieving targets, which should promote increased ambition over time. This should enable all countries to follow a low-carbon and resilient development pathway in line with the global goal to hold the increase in global average temperature below 2 degrees Celsius.

The G7 nations also re-committed to providing at least $100 billion a year from 2020 to assist developing countries in shifting their economies to renewable sources of energy and adapt to negative impacts from global warming, as agreed to at a 2009 summit in Copenhagen.

So far, country commitments have fallen far short of that $100 billion figure, with just $5.5 billion pledged to-date. Provision of adequate climate finance is a key concern of developing nations, as is the source of that money, since private sector loans and money from institutions like the World Bank would need to be paid back, and are therefore opposed by most developing countries.

Seeking buy-in from Africa

The G7 countries also pledged to increase developing countries' ability to withstand climate impacts, from sea level rise to more frequent and intense climate extremes. One such method would be through direct or indirect insurance policies that would help increase societal resilience to climate change. The specific goal set by the G7 is to increase those who have access to such insurance policies by 400 million people. Notably, the G7 leaders declaration also endorses work to spread renewable energy technology to Africa as a way to expand the availability of electricity there without increasing greenhouse gas emissions. Several African leaders were present at the G7 meeting, including the newly elected president of Nigeria.

In the past, Africa has been a major player in the U.N. climate talks, typically allying with small island states to push for more aggressive emissions reduction targets, and scuttling agreements crafted mainly by industrialized nations.

The engagement with African nations ahead of the Paris talks may indicate that industrialized nations are seeking to head off African resistance to a draft climate agreement before the Paris summit begins on November 30.

"Their commitment to increase renewable energy access in Africa and address climate risks from disasters will help build trust with developing countries ahead of the climate negotiations in Paris," Morgan said of the G7 Africa commitment. “While more remains to be done — particularly around meeting the $100 billion goal — it is clear G7 leaders understand that delivering climate finance is a part of their role in the global community."

The G7 also committed to eliminate "inefficient fossil fuel subsidies" while encouraging other countries to do the same. A recent International Monetary Fund study concluded that global fossil fuel subsidies amount to $5.3 trillion per year.

The largest subsidies are provided by China, the U.S., Russia, India, Japan and the EU.