Latin American and Caribbean governments have a huge opportunity to safeguard the future well-being and prosperity of people across the region during the Rio de Janeiro meeting this week at the United Nations Conference on Sustainable Development.

The conference will seek an agreement among both rich and poor countries about how to achieve the three goals of promoting economic growth and overcoming poverty, increasing social justice and reducing inequality, and protecting and nurturing the environment and the global commons, such as the oceans and the atmosphere.

However, there have been some suggestions that these three objectives are “in tension,” and that success in achieving one requires the sacrifice of another. Some seem even to claim that protecting the environment can or should be neglected in order to focus on the others. That is confused thinking — in fact, all three goals reinforce each other and each cannot be successfully realized without progress on the others.

Unmanaged climate change has immense economic costs and poses a deeply serious threat to the lives and livelihoods of poor people in Latin America and the Caribbean, and across the world. “Business as usual” emissions of greenhouse gases risk global warming of 5°C or more to temperatures not seen on Earth for more than 30 million years.

Countries agreed at the United Nations climate change conference in Cancun in December 2010 that annual emissions should be reduced to avoid global warming of more than two centigrade degrees. To have a reasonable chance of this, annual emissions will have to be reduced from the present level of about 50 billion tons to less than 35 billion tons in 2030 and well below 20 billion tons in 2050.

Given that the global population is likely to reach nine billion by 2050, this means that average emissions across the world will need to be no more than about two tons per capita. The current global average for per capita emissions is about seven tons. Total emissions of greenhouse gases by Latin American and Caribbean countries were about 4.7 billion tons in 2010, or about 8.0 tons per capita.

The rich countries are clearly responsible for the overwhelming bulk of historical emissions and still emit many more times than the average today — for example, the United States emits about 22.1 tons per capita and the European Union emits about 9.4 tons. It is the rich countries which must lead by example in cutting their emissions sharply.

But even if the rich countries managed to reduce their emissions to zero by 2030, the rest of the world on average would have to hold emissions below five tons per capita in 2030 and 2.5 tons per capita in 2050 to keep to a global emissions pathway consistent with the target of two centigrade degrees.

While this will be a huge challenge, Mexico, Colombia and other Latin American and Caribbean countries are already showing leadership by drawing up plans to adapt to those impacts of climate change that cannot now be avoided, and also reducing their emissions to limit the risks of even greater warming.

There are also significant economic opportunities associated with moving to low-carbon growth, particularly of being at the forefront of a new energy and industrial revolution that is already taking off. And as the Cancun agreement makes clear, reducing greenhouse gas emissions can be consistent with equitable access to sustainable development.

Latin American and Caribbean countries can demonstrate leadership on climate change and sustainable development in Rio, not just in terms of what they have already achieved, but through their ambition for the future. The 1992 Rio Summit was a landmark for the region in terms of the institutional change required to incorporate sustainable development objectives. But the world has underperformed relative to the 1992 vision. The delay has been destructive and dangerous.

The world cannot afford to miss this opportunity to accelerate our efforts.

José Antonio Ocampo is a professor at Columbia University and formerly United Nations under-secretary-general for economic and social affairs and finance minister in Colombia. Nicholas Stern is chair of the Grantham Research Institute on climate change and the environment at London School of Economics and Political Science and formerly chief economist at the World Bank.