The leaders of the countries with the largest carbon emission, U.S. President Barack Obama and China President Xi Jinping, met at the sidelines of the World Climate Change Conference 2015 (COP21) at Le Bourget, Paris, France on Monday. The two world leaders agreed on taking necessary actions in their fight against global warming.

"What should give us hope that this is a turning point, that this is the moment we finally determined we would save our planet, is the fact that our nations share a sense of urgency about this challenge and a growing realization that it is within our power to do something about it," Obama said in his speech during the summit as quoted by Reuters.

Meanwhile, Xi also gave an assurance that there is a partnership going on between the U.S. and China in response to the global challenge. "Tackling climate change is a shared mission for mankind," Xi said during his speech at COP21.

Since China has been surrounded in hazardous, choking smog, and Beijing is in the "orange" pollution alert, which is the second-highest level of pollution, it is necessary for the country to take steps to help lessen the greenhouse gas emissions along with the U.S. since it is one of the biggest developed countries in the world, Xinhua Net reports.

It has been reported that the U.S. and China account to 40 percent of the global greenhouse gas emission, which further stress that their cooperation is vital at this time.

"Nowhere has our coordination been more necessary or more fruitful than the topic that we're here to discuss during the Paris conference, and that is how the world can come together to arrest the pace of climate change," Obama said as quoted by Xinhua Net.

Apparently, the anticipated summit had long been planned and was even canceled during the Copenhagen chaos and acrimony in 2009, per Reuters. This time, Xinhua Net states that the meeting reportedly aims to produce a new international agreement to reduce greenhouse gasses beyond 2020 when the 1997 Kyoto Protocol expires.

According to Reuters, projections, in terms of the global environmental status, include hotter average temperatures, deadlier storms, more frequent droughts and rising sea levels as polar ice caps melt.

With this, the world leaders in many nations will bear pledges to reduce their national carbon output through different measures at different rates since they are responsible to 90 percent of the world's greenhouse gas emissions.