We have a climate treaty－but at what cost?

United Nations Secretary General Ban Ki-moon, accompanied by French Ecology Minister Segolene Royal (L), French Foreign Affairs Laurent Fabius (2ndL), Secretary of the UN Framework Convention on Climate change Christiana Figueres(3rdL) and French President Francois Hollande (3rdR) , welcomes Chinese President Xi Jinping as he arrives for the opening day of the World Climate Change Conference 2015 (COP21) at Le Bourget, near Paris, France, November 30, 2015. [Photo/Agencies]

After two weeks, huge amounts of political rhetoric, and much activity behind closed doors at the Paris climate change conference, we have a treaty. While there will be celebrations among activists, the Paris Treaty will do very little to rein in temperature reductions.

The Paris Treaty promises to keep temperature rises below 2 degrees Celsius. However, the actual promises made here will do almost nothing to achieve that.

The United Nations Framework Convention on Climate Change estimates that if every country makes every single promised Paris Treaty carbon cut between 2016 and 2030 to the fullest extent possible and there is no carbon leakage, CO2 emissions will be cut by 56 billion gross tons by 2030. The math is simple: in an implausibly optimistic best-case scenario, Paris leaves 99 percent of the problem in place.

To say that the Paris Treaty will get us to 2 C is cynical posturing at best. It relies on wishful thinking. It's like going on a diet to slim down, but declaring victory after the first salad.

Paris will be extraordinarily costly. It is likely this is the most expensive treaty in the history of the world.

Using the best individual and collectively peer-reviewed economic models, the total cost of the Paris Treaty－through slower GDP growth from higher energy costs－will reach $1 trillion to $2 trillion every year from 2030.

We owe the world much more－both in terms of tackling climate change better, and in spending resources smarter.

The best thing to come out of Paris was the announcement of the Bill Gates-led green energy innovation fund together with private individuals and governments, including those of Australia, the United States, Brazil, Canada, Chile, China, Denmark, Germany, France, Saudi Arabia, Sweden, South Korea, and the United Arab Emirates. This is an excellent initiative. I have argued for greater spending on research and development for a decade. Even more funding is needed, and the Gates-led fund is what is really going to make a difference to the climate.

Until there is a breakthrough that makes green energy competitive on its own merits, massive carbon cuts are extremely unlikely to happen. Claims that carbon cuts will be free or even generate economic growth don't stack up given today's technology. Every economic model shows real costs. If not, we wouldn't need the Paris Treaty: every nation would stampede to voluntarily cut CO2 and get rich.

The agreement to spend $100 billion on climate aid is a poor way to help the developing world. Their citizens clearly say, this is their lowest policy priority and climate aid provided by handing out solar panels has meager benefits compared with the many better, cheaper ways to help, like investing in immunization, girls' education and family planning. While billions of people lack food, healthcare, water and education, distributing solar panels is simply immoral.

The Gates innovation push is great news and the only way we can start tackling the 99 percent of the climate problem not addressed by Paris. After Paris, I will be advocating for an even greater investment in green energy research and development. Funding in the region of $100 billion annually is what is needed.

The author is director of the Copenhagen Consensus Center and visiting professor at Copenhagen Business School.