There are plenty of options for offsetting your company's carbon emissions, but what about your website's? Most businesses rely on outside vendors for server space and other website requirements, but there are limited options for even calculating the power needs of a given website, let alone offsetting them. CO2Stats is working on filling that niche.

CO2Stats uses a surprisingly simple method to calculate the carbon emissions of a given site. The company requires that participating websites add a small snippet of HTML code — it displays a 'Green Certified Site' logo as well as performing a series of calculations that aren't visible to the sites' users. There are several versions of the CO2Stats program, depending on how many page views a website owner wants to offset. The free version offsets only the first 100 page views for a participating website in any given month. The premium (in other words, most expensive) service that CO2Stats offers covers up to five million page views each month and is priced at $99.95 monthly.

The CO2Stats offset program covers not only the energy necessary to run a given site's server, but also the power needs of visitors to the site based on their locations and a set of publicly available statistics. CO2Stats' goal is to offset the entire carbon footprint of participating websites. The company handles purchasing renewable energy certificates for participants: CO2Stats purchases Green-E Certified renewable energy certificates from Sustainable Travel International and Native Energy. The purchasing process is CO2Stat's moneymaking operation — because it can buy in bulk, CO2Stats turn a profit on the fixed monthly fees charged to participating websites.

The founders of CO2Stats are Alexander Wissner-Gross and Timothy Sullivan. The two attended a computer conference in Beijing together in October 2007. The high levels of air pollution in Beijing led the two to create a startup that would reduce the environmental impact of the Internet. More than 2,500 websites have registered with CO2Stats since then, offsetting the web usage of millions of visitors.

Internet usage — and the power needed for all those websites — grows every day. But many businesses simply don't take their websites into account when calculating their carbon footprint. Part of the issue is that it seems complex: what metric should you use when considering visitors to the site? But CO2Stats has developed a metric, and made measurement a matter of copying and pasting code. CO2Stats' approach seems ideal for most companies.