By Katie Ellington, News Editor

Just two weeks after the devastating attacks in Paris, almost 150 world leaders arrived in the French capital on Sunday for the 21st Conference of Parties (COP21), a two-week conference dedicated to global climate change.

This call to decrease greenhouse emissions worldwide is not new. The United Nations tried unsuccessfully to enforce global change through the 1997 Kyoto Protocol. It later drafted a new pact at the 2009 Copenhagen Accord which failed to garner a unanimous vote. Despite previous problems, an article in TIME magazine indicates that the COP21 may be more fruitful due to the inclusion of member nation’s individual plans, known as Intended Nationally Determined Contributions (INDC). These INDCs are based on what each country believes it can realistically carry out. Both President Obama and Chinese President Xi Jinping have shown public support for climate change efforts for years. Both announced major emissions reduction policies last year, spurring a trend that resulted in over 170 countries putting forth their own proposals. TIME’s Justin Worland says that the COP21 agreement will ensure the nations will implement their plans and that the developed nations will help developing ones through financial aid.

Attendees include member parties of the United Nations Framework Convention on Climate Change. It is the convention’s third attempt to create and pass a legally binding contract requiring all member nations to reduce their carbon emissions. World leaders hope to slow the increase in the global temperature before it reaches an overall increase of two degrees above the pre-Industrial average.

The two degree benchmark was first mentioned in 1977 by William Nordhaus, a professor of economics at Yale University. Nordhaus noted that a two degree increase would be the largest in recorded history. Ever since, scientists have been studying and predicting the potential outcomes of a two degree increase. Reports indicate that global temperatures have already risen by at least one degree; scientists warn that another could have massive consequences: rising sea levels, species extinction, a decrease in certain crop yields, less freshwater and more natural disasters including droughts, hurricanes, floods and wildfires. According to a CNN article, one NASA report predicted that if greenhouse gas emissions do not decrease, the western half of the United States could see droughts lasting up to forty years by 2100.

While the two degree standard has been endorsed by numerous scientists and political groups (including the European Union), support within the scientific community is not unanimous. An article featured in the Wall Street Journal indicated that some scientists believe the standard is inadequate. Some scientists have rejected the number as too hypothetical. On the other hand, professor of international relations David Victor stated that we are already headed towards the two degree mark and there is no feasible to stop it. Victor and Charles Kennel, a professor at Scripps Institution of Oceanography, contested the benchmark in October 2014 because it doesn’t account for the increasing temperatures in the ocean, which contains 93 percent of the world’s extra heat.

Given the scale of the challenge, we need to be exploring many different paths, and that means we also need to invent new approaches.

The conference started out with a bang on Monday, when the co-founder of Microsoft, Bill Gates held an event for Mission Innovation. According to the Huffington Post, Mission Innovation consists of 19 countries and 28 leading investors pledging billions to develop clean technology. The Huffington Post reported that the event gained Mission Innovation another supporter when Canadian Prime Minister Justin Trudeau promised $300 million a year.

“Given the scale of the challenge, we need to be exploring many different paths, and that means we also need to invent new approaches,” Gates said on a statement.