Obama UN US President Barack Obama addresses the United Nations General Assembly in New York September 20, 2016 REUTERS/Kevin Lamarque

Obama gave his final address to the United Nations on Tuesday, where he discussed how investing in new technologies can help combat climate change, among other issues.

He highlighted the need for a "new model" for the global marketplace, one that's both environmentally sustainable and inclusive of rich and poor countries. 

The address came just a day before Obama signed a Presidential Memorandum requiring the federal government to consider climate change when setting national security policies.

In the address, Obama said that "investing in research" and providing "market incentives" to develop new technologies is critical to fighting climate change and greenhouse gases.

He also discussed the landmark Paris climate deal, signed in December 2015, giving it another boost in front of world leaders.

Obama said that the agreement — which was ratified by both the US and China when Obama visited Hangzhou for the G20 conference earlier in September — gives the global community a "framework to act," but only if we "scale up our ambition."

On Wednesday, thirty-one more countries officially ratified the Paris climate deal, in New York, including Mexico, Brazil, and the United Arab Emirates, reports PBS. Countries who sign the deal must work to keep the average global temperature from rising more than 2 degrees Celsius. 

climate change global warming The drought in Syria forced over half a million people to leave the country for the cities, stirring tensions that eventually led to the country’s civil war. Khaled Al Hariri/Reuters

"There must be a sense of urgency about bringing the agreement into force," Obama said, noting that the agreement will help developing countries "leapfrog" to cleaner energy sources. 

"And only then can we continue lifting all people up from poverty without condemning our children to a planet beyond their capacity to repair," he said. 

Obama also said that the Green Climate Fund — an international fund that helps poor countries adapt to climate change — is "only the beginning." The US gave $500 million to the fund in March, the first payment out of a promised $3 billion.

In his speech, Obama warned that if the global community doesn't "act boldly," the next climate agreement will be due to "mass migrations, and cities submerged and nations displaced, and food supplies decimated, and conflicts born of despair."

Climate change and national security

Obama's Presidential Memorandum, released on Wednesday, called for the federal government to "fully consider the impacts of climate change in the development and implementation of all national security policies and plans."

The president has said that climate change will be one of his top priorities after leaving the Oval Office.

Louisiana flooding Brittany Addox (R) comforts her dog, Maggie, after being rescued in Ascension Parish, Louisiana. REUTERS/Jonathan Bachman

"Around the world, climate change will only continue to threaten the stability of countries, heighten social and political tensions, increase health risks, jeopardize food security, and negatively impact economic growth," The White House's announcement reads. 

The announcement, supported by a National Intelligence Council report released on Wednesday, points out that a "devastating drought" contributed to conflict in Syria. The report concludes that climate change is likely to "pose significant national security challenges for the United States."

"Responsible Scientists"

On the other hand, Donald Trump, the Republican nominee, has said that he would pull the US out of the Paris climate agreement if he were to be elected president. 

Hundreds of climate experts, calling themselves "Responsible Scientists" rebuked the "Republican nominee for president" in an open letter published on Wednesday. 

The letter, without naming Trump directly, said that his positions on climate change were "inconsistent with reality."

"Human-caused climate change is not a belief, a hoax, or a conspiracy," the letter reads. "It is a physical reality."

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