Correction: An earlier version of this op-ed incorrectly reported that the Organization for Economic Co-operation and Development determined one-third of all aid from the United States and other rich nations is climate related. One-fourth of all aid from the United States and other rich nations is climate related. This version has been corrected.

Bjorn Lomborg is president and founder of the Copenhagen Consensus Center and a visiting professor at Copenhagen Business School.

The election of Donald Trump and Republican majorities in both houses have terrified environmentalists and climate campaigners, who have declared that the next four years will be a “disaster.”

Fear is understandable. We have much to learn about the new administration’s plans. But perhaps surprisingly, what little we know offers some cause for hope.

It should not need to be restated in 2016 that climate change is real and mostly man-made. It is hard to know whether Trump will acknowledge this. He has called global warming a “hoax” perpetrated by the Chinese, but stated that this was a joke; he denied the existence of climate change during the campaign, but supported global warming action as recently as 2009.

What really matters is not rhetoric but policy. So far, we know that President Trump will drop the Paris climate change treaty. This is far from the world-ending event that some suggest and offers an opportunity for a smarter approach.

France tells U.S. President-elect Donald Trump that the Paris accord on climate change is "irreversible" and that the U.S. will be affected by rising oceans and natural disasters. (Reuters)

Even ardent supporters acknowledge that the Paris treaty by itself will do little to rein in global warming. The United Nations estimates that if every country were to make every single promised carbon cut between 2016 and 2030 to the fullest extent and there was no cheating, carbon dioxide emissions would still only be cut by one-hundredth of what is needed to keep temperature rises below 3.6 degrees Fahrenheit (2 degrees Celsius). The Paris treaty’s 2016-2030 pledges would reduce temperature rises around 0.09 degrees Fahrenheit by the end of the century. If maintained throughout the rest of the century, temperature rises would be cut by 0.31 degrees Fahrenheit.

At the same time, these promises will be costly. Trying to cut carbon dioxide, even with an efficient tax, makes cheap energy more expensive — and this slows economic growth.

My calculations using the best peer-reviewed economic models show the cost of the Paris promises – through slower gross domestic product growth from higher energy costs — would reach $1 trillion to $2 trillion every year from 2030. U.S. vows alone — to cut greenhouse-gas emissions 26 percent to 28 percent below 2005 levels by 2025 — would reduce GDP by more than $150 billion annually.

So Trump’s promise to dump Paris will matter very little to temperature rises, and it will stop the pursuit of an expensive dead end.

However, Paris was a well-meaning — if flawed — attempt to address a genuine global issue. With no international climate policies at all, it is probable that we would see a temperature rise of perhaps 7 degrees Fahrenheit by the end of the century. The United States needs to find a smarter solution. Climate economists have found that green energy R&D investment would be a much more efficient approach.

This is very much in line with Trump’s campaign promise of “investment in research and development across the broad landscape of academia” and with its suggestion that we could develop “energy sources and power production that alleviates the need for dependence on fossil fuels.”

This investment in U.S. ingenuity could help innovate the price of green energy down below fossil fuels. Only then will we truly be able to stop climate change.

Statements by Trump’s campaign also indicate that the next administration will create a global development and aid policy that recognizes that climate is one problem among many.

Asked about global warming, the campaign responded, “Perhaps the best use of our limited financial resources should be in dealing with making sure that every person in the world has clean water. Perhaps we should focus on eliminating lingering diseases around the world like malaria. Perhaps we should focus on efforts to increase food production to keep pace with an ever-growing world population.”

This would be a big change. The Organization for Economic Co-operation and Development analyzed almost all aid from the United States and other rich nations and found that about one-fourth is climate-related aid.

This is immoral when 2 billion people suffer from malnutrition, 700 million live in extreme poverty and 2.4 billion are without clean drinking water and sanitation. These problems can be tackled effectively today, helping many more people more dramatically than “climate aid” could.

Despite its length, and for all of its heat and bluster, the election campaign left many unanswered questions and understandable concerns about the president-elect’s positions on climate change, aid and development.

But, surprisingly, there is now an opportunity. To seize it, the Trump administration needs to go beyond just dumping the ineffective Paris agreement, to an innovation-based green energy approach that will harness U.S. ingenuity. Far from being a disaster, such a policy could mean a real solution to climate change and help the world’s worst-off more effectively.