Microsoft achieved its goal of becoming carbon neutral by July 1, 2013, according to a report by the Natural Resources Defense Council.

The NRDC review of progress against commitments that companies, countries and other bodies made at the June 2012 Rio+20 conference reports that Microsoft fully achieved its goal of carbon neutrality. Microsoft had pledged to achieve zero net carbon emissions for its all data centers, offices, software development labs and employee air travel.

Microsoft began charging an internal fee for carbon associated with the use of electricity and business air travel on July 1. As a result, departments planning future business growth have had to consider the carbon fee associated with operations. The NRDC says the fee is between $5 and $7 per ton of carbon. The fee generated over $8 million, used to finance grant programs for efficiency and travel reduction, fund renewable energy and carbon offsets, buy renewable energy certificates and plan long-term power purchase agreements.