Why scientists say COP21 will fail

For almost two decades now, countries around the world have consistently failed to reach an agreement on climate protection. Even the famous Kyoto Protocol of 1997 was not truly global, with only 37 industrialized countries pledging to meet climate goals.

Since then, there have been countless summits and dramatic calls to action - but effectively no results. The upcoming UN climate summit in Paris will rely on a new formula: Countries will pledge to reduce their emissions by amounts they determine themselves. These so-called “Intended Nationally Determined Contributions" will then be reviewed later.

But even that will fail, says David MacKay of the University of Cambridge, an acclaimed researcher of sustainable energy.

"There's a widespread belief that success for climate change action is all about altruism or ambition," MacKay told DW.

"So you want to persuade people to take actions that are in the interest of the common good, and might not be aligned with people's self-interest."

According to MacKay, this approach ignores 40 years of research in the science of cooperation and game theory. In climate negotiations, countries have strong incentives to go for a free ride, waiting for others to act while not reducing their own emissions.

That is what scientists call "the tragedy of the commons."

Between self-interest and altruism

If the national climate action plans submitted by 146 countries before the summit are any indication, MacKay might be right.

"Many of the pledges are just pledging what countries would have done out of pure self-interest anyway - so they're actually pledging nothing," he says. "China, for example, pledged to reduce coal use compared with an absurd scenario where they would have polluted their whole country and had terrible health problems. So actually, what China is pledging to do is just consistant with self-interest - reducing the health problems from coal use."

The United Nations' top climate director, Christiana Figueres, has praised the pledges as "clear and determined," but had to admit they were not sufficient to reach the big goal of limiting global warming to less than 2 degrees. She added that she hopes the pledges are "not the final word in what countries are ready to do."

But actually, it's quite easy to bridge the huge gap between countries' self-interests and global climate goals, MacKay and economists Peter Cramton, Axel Ockenfels and Steven Stoft believe.

One carbon price for all

Instead of endlessly haggling over emission goals, the international community should simply focus on a global price for carbon emissions - and observe the principle of reciprocity.

"That means: I will do something if you do something, and I won't if you won't," says MacKay. "I will apply a carbon price in my economy if everyone else applies the same carbon price in their economy."

Countries would be free to choose how the carbon price would be reached - be it through emissions trading schemes, a carbon tax or other means.

"It's quite possible for a country - even if they don't care about climate change - to say: Yes, carbon taxes will be a handy source of revenue for the next few decades," MacKay says. "And that would allow them perhaps to reduce taxes on other things."

In search of a balance

But even then, countries like China or India would bargain for the lowest possible price for a ton of CO2, arguing a higher price would be an unfair burden on their developing economies, and pointing to the fact that their per capita pollution is still much below the levels in industrialized countries.

To ensure an acceptable burden sharing, says MacKay, a "Green Climate Fund" should be set up and transfer money from rich to poor countries. "You can incentivize countries like India to actually vote for a higher carbon price, because that would give them higher Green Fund transfers."

Rich countries, on the other hand, would try to limit the money they would have to pay into the fund, and therefore vote for a slightly lower carbon price, MacKay believes.

"The negotiation could then be about finding the sweet spot where you get India and America both agreeing on the strongest possible carbon price - and everyone agreeing with them as well."

$10 per ton

"If you could get a global agreement of at least $10 per ton, we think that would actually have a stronger effect than what the Paris negotiations are likely to produce," says MacKay.

Until 2014, MacKay served as Chief Scientific Adviser to the UK Department of Energy and Climate Change (DECC). He and his economist colleagues have recently published their proposal for a different form of climate negotiations in "Nature," a renowned British scientific journal, but have little hope their ideas will be considered during the summit in Paris.

"If Paris ends up as not a great success, we want it to be clear that there was a different way of doing the negotiations," he says. "It is possible to change the rules of the game so that self-interests are aligned."

If MacKay and his colleagues are right, future climate negotiations could turn out to be a walk in the park.