Creating sustainable technologies that will lessen the human impact on the natural environment is becoming more and more of a concern, especially in Europe, where public pressure to clean up the atmosphere is intense and growing. In response, companies are offering "carbon offsets" that, for a price, will neutralize the carbon emissions from aircraft in various ways, either planting trees to absorb carbon dioxide or investing in alternative forms of energy to prevent more emissions. Whether or not this is actually effective is open to debate, but the concept has caught fire, and now the offsets are being offered not just to airline passengers but also to those who use private jets. The issue of climate change has arrived in the aviation sector, Jonathan Shopley, CEO of The CarbonNeutral Company, told the London Times. Every company is thinking about what they are going to do about it." Air Partner, an air charter company operating a Cessna Citation XLS for celebrity clients, is the first charter operator to offer carbon neutral flights, according to the Times. Customers can buy the Carbon Neutral JetCard for an extra 2-percent premium over the regular cost. A report released this week by Clean Air - Cool Planet ranks carbon-offset companies according to their effectiveness.