How can we ensure that protectionists do not hide behind concern for the environment to restrict internationally traded goods and services?

Although climate change presents very serious enviromental challenges, its also provides good business opportunities, new thinking and innovation. The issue of carbon footprint should not be used at all times to restrict internatonally traded goods and services. According to  the Financial Times of Friday, January 4, 2008, 'It creates a smallers carbon footprint, for example, to grow flowers in east Africa and fly to London than it does to raise them in heated greenhouses in Europe itself'.