Mexican President Felipe Calderon has signed into law climate change legislation that will bind the country to significant cuts in greenhouse gas emissions and increase the use of renewable energies within the next few decades.

With the legislation I signed, Mexico becomes the first developing country with a comprehensive law against climate change, Mr. Calderon posted on his Twitter account Tuesday.

The law, which sets targets for emissions cuts as well as for the expansion of renewable energies, is only the second of its kind in the world after Great Britain and represents the first initiative of a developing country to commit to such targets.

By 2020, Mexico aims to cut its greenhouse gas emissions by 30 percent, and by 50 percent by 2050. It also calls for 35 percent of Mexico's energy to come from renewable sources by 2024 and requires government agencies to use renewable energy.

This law adds to the efforts that have positioned Mexico as an international leader in environmental protection, Mr. Calderon wrote in another Twitter post.

Mexico is ranked 12th among the world's top carbon-emitting countries, producing 443.61 million metric tons of CO2 every year which accounts for less than 1.5 percent of global carbon emissions, according to the most recent data gathered by the U.S. Energy Information Administration.

The world's largest carbon emitters are China and the U.S., producing 7.7 billion and 5.43 billion metric tons of CO2 per year respectively, together accounting for over 40 percent of global carbon emissions.

Neither China nor the U.S. have passed any climate change legislation to reduce greenhouse gas emissions or increase use of renewable energies. Only the U.K., which ranks eighth in carbon emissions, has passed similar legislation, with a 2008 law committing to cut emissions 50 percent by 2050.

In late 2010, Mexico hosted the 16th U.N. Climate Change Conference, known as COP 16, which aimed to build a framework for global emissions cuts. Governments reaffirmed that human-generated emissions contribute to rises in global temperature and agreed to keep average global temperature below an increase of two degrees Celsius, though few substantive commitments were made in the way of achieving this goal.

According to Climate Action Tracker, an independent climate change research group, current global emissions are setting average global temperature on a path toward a rise of 3.5 degrees Celsius by 2100.  

It's clear that many governments are nowhere near putting in place the policies they have committed to, policies that are not enough to keep temperature rise to below 2 degrees Celsius. We've already identified a major emissions gap and the action being taken is highly unlikely to shrink that gap -- indeed it seems that the opposite is happening, said Bill Hare, Director of Climate Analytics and member of the CAT research team, in a statement last month.

CAT has accumulated data on emissions for every country that pledged to keep average global temperature from rising. Citing the U.S. pledge to reduce carbon emissions to 17 percent below 2005 levels by 2020, CAT rated its progress as inadequate. Similarly, China, which pledged to reduce emissions per capita by 40-45 percent by 2020, was also rated inadequate.

Mexico was given a more positive evaluation for its policy efforts, but CAT emphasized that the country must focus on how it will implement those policies if it is to stick to its targets.

Mexico has performed well on the international stage, both in helping to get international agreements and showing a strong commitment to developing its own national institutional and strategic framework, said Marion Vieweg, a policy analyst for CAT.

However, more action is needed to meet its current targets. With the adoption of the climate change law, Mexico now needs to put more effort into actually implementing specific policies that secure long term action.