The marketing of carbon offsets [3] as a 'solution' to global warming is attracting criticism. The theory is that an individual or organization can pay a company to invest in renewable energy or tree planting projects to offset carbon emissions from travel or other activities. Speaking at a protest at the office of the UK-based The Carbon Neutral Company [4] (TCNC), Sam Chase from London Rising Tide described offsetting as "a smokescreen". Carbon Trade Watch, a project of the Amsterdam-based Transnational Institute, recently released a report [5] (pdf) critiquing offsets. "Offset companies give the idea that emissions are instantly 'neutralised' when in fact the supposed 'neutralisation' can take place over periods of up to a hundred years. Regular offsetting worsens the problem because the rate at which carbon emissions are 'neutralised' is far slower than the rate at which they are generated," warns Kevin Smith, the report's author.