This blog post was originally published in Portuguese by Folha de S.Paolo on August 20, 2015.

Leia a versão em Português desta postagem clicando aqui.

The world is losing the window of opportunity to solve the climate crisis. To have a reasonable chance of limiting global warming to 2°C and avoid its most dramatic effects, we need to limit all carbon dioxide emissions (CO2) to one trillion metric tons.

Based on current trends, the "safe space" of carbon to limit global warming will be surpassed in less than 30 years. To reach the 2°C target, a radical and urgent decarbonization of the global economy will be necessary. A difficult task, but still possible.

A global commitment to decarbonization should be signed in December this year, during the Climate Conference in Paris. Until October, countries will present emissions-cutting proposals, known as INDCs (Intended Nationally Determined Contributions).

The safest path for humanity require emissions reductions to the order of 60 percent to 7 percent by mid-century. In other words, per capita emissions should converge to no more than two tons of CO2 equivalent (CO2e) in 2050.

Currently, the per capita annual emissions from the US (18.6 tCO2e), Russia (15.8 tCO2e), Germany (10 tCO2e), China (7.9 tCO2e) and Brazil (7.5 tCO2e) are above the per capita global emissions (6.4 tCO2e).

The sum of the INDCs presented as of today, however, is not encouraging: they cover only 2 percent of the necessary emission reductions. By 2030, every U.S. citizen would be emitting 17 tCO2e on average; every Russian, 13 tCO2e, every German, 8.8 tCO2e; and every Chinese, 9.6 tCO2e. From the perspective of per capita emissions, it is clear that the convergence to the desirable values is still very slow.

The conference in Paris opens an opportunity not to be missed for Brazil to continue setting an example. From the current 7.5 tons of CO2e of per capita emissions, we could reach 4 t per year in 2030. A reduction of over 40 percent. The target already announced of 12 million hectares of forest restoration by 2030, coupled with the continuing decrease in deforestation rates, indicates that achieving zero net emissions in land use change is feasible.

Thus, the majority of Brazil's emissions would focus on two sectors: agriculture and energy. In agriculture, emissions increased by just over 4 percent from 2005 to 2012, but the agricultural GDP grew by 16 percent over the same period, showing a trend towards greater efficiency, which can be further accelerated with the Low Carbon Agriculture Plan, and technologies to increase productivity and revenue to consequently reduce emissions.

Energy emissions have grown with the increase in population and GDP. It is possible to decouple the two curves until 2030 with energy efficiency and investments on non-traditional renewable energy.

Studies from the Federal University of Rio de Janeiro (UFRJ) show that wind and solar power plants near transmission lines face less intermittency of supply when there is little wind or sun. These sources can generate at least 300 to 350 gigawatts, respectively. It represents four times more than all our current electricity generating facilities.

In short, it is possible for Brazil to reach 4 tCO22e per capita emissions in 2030, with benefits for the economy and the population. It would pave the way for the continuation of emission reductions, with the goal of reaching 2 tCO2e per capita in 2050, when our energy mix could be almost 100 percent clean and renewable.

This is the sustainable country, and world, we want to leave for our children.

Carlos A. Nobre is one of Brazil’s top climate scientists, member of the Brazilian Academy of Science and Foreign Member of the U.S. National Academy of Sciences. He is a founding member of WRI Brasil and served until recently on its Board of Directors. In the period 2011–2015, he served as Secretary for Science Policy in the Ministry for Science, Technology and Innovation in Brasilia. In May 2015, he assumed the Presidency of CAPES, a foundation responsible for support of graduate and post-graduate education i, under Brazil's Ministry of Education (MEC). In this post, he explains why an ambitious Brazil should aim for to help the world reach a successful agreement in the upcoming Climate Conference in Paris.