Donald Trump's presidency is going to be a game-changer for the world. The impacts that it will have on major world issues such as terrorism, racism and global finance have been extensively discussed in the public sphere. Trump has claimed that he will make America "great again" by applying the same principles that have made him a business tycoon. Many of Trump's supporters believe that his methods will make all Americans richer and more successful like Trump himself. However, environmentalists are not impressed by this rhetoric. Businessmen are generally known to only think in terms of profit and loss. From this perspective, the environment can be degraded as long as it is profitable to do so. The US needs a responsible leader who will make the planet more sustainable by taking into account the needs of future generations; however, their new President is just another powerful businessman who could not care less about the environment.

Throughout the presidential campaign, Trump had made fantastical remarks about serious issues and proposed radical policies for dealing with them. His solution for terrorism was to ban Muslims from entering the United States while his way of reducing abortions was to punish the doctors who performed them. His stances on the environment are no exception. He has made it clear that he thinks that global warming is a hoax. It is not unusual for Trump to make claims without feeling the need to back them up with any kind of fact or logic. He simply chooses to ignore the large body of scientific evidence that suggests the need for drastic measures for combatting climate change. Human induced climate change is now a fact recognised not only by scientists but also the majority of world leaders as evidenced by their participation in the recent COP21.

COP21 is an environmental agreement between 195 countries that was made in December 2015 in Paris. The aim of this agreement is to limit global warming by switching from fossil fuels to renewable sources of energy over the next 50 years. Even though this deal has legal aspects, it cannot be enforced on any country that wants to break away. This is especially true with a powerful country such as the US, which can afford to affront others without suffering major consequences. Republicans in general do not approve of cutting carbon emissions. Therefore, the future of the deal would be grim if any Republican was elected president, not just Donald Trump. However, even a Republican President with integrity would respect a deal signed by a previous president of the United States. Trump has made it clear that he wishes to renege on the deal signed by President Obama. 

Trump may not be able to pull out from the deal completely, as a four year binding commitment has been made, but he can slow down the much needed progress. This would be the best case scenario. The worst case scenario is that the COP21 agreement would break down completely because of the US' lack of support. The US is the second largest user of fossil fuels after China. Their backing out of the pact would not only make a big difference by itself but it might also encourage other important countries such as India and China to do the same. All countries that signed the deal will have to sacrifice some of their present economic growth in order to preserve the environment for future generations. Doing so is not easy for any politician because politicians require their popularity in present times. They do not gain popularity or success by making sacrifices for the future. This is why environmental sustainability requires responsible leadership. A leader who is egocentric and popularity-centered will not understand the importance of making sacrifices in the present in order to create a better future.

Scientists say that human-induced climate change has already begun, and the best that the COP21 deal can do is limit the rise in temperature. Sea level rise due to global warming is already happening. The effects of global warming on melting ice caps and subsequent sea level rise increase exponentially with each degree of rise in global temperature. The aim of the COP21 is to limit the rise in temperature as much as possible so that the environment is damaged as little as possible. If major countries such as the US do not follow through on the deal, there may be an irreversible climate catastrophe which will have yet unprecedented effects on human society. 

While the future does look grim, all hope should not be lost. Environmental activists have been able to prevent politicians from making harmful deals in the past and they still hold quite a lot of power. There are many powerful figures around the globe who support action on climate change including the Pope, the Queen and many artists and celebrities. As President Obama has recently commented on the Trump presidency, "Reality has a way of asserting itself". Despite Trump's claims during his campaign, it is possible that he will act in a responsible way under the right kinds of pressure. 

The writer is a graduate of Macquarie University, Australia.