Environmental challenges, ranging from the smog in cities to toxic groundwater to the Antarctic ozone hole have been presented to us. I believe that many of these challenges should be met with collaboration across national boundaries. Environmental concerns should be dealt with through joint efforts from countries for two main reasons. The first one is now problems such as oil spills and dust storms are so widespread that they can hardly be confined to one single country or region. Thus, it is crucial that these problems be solved with international efforts. What is meant by this is each country and person should be made aware of their unique role in environmental protection. The second reason why joint effort is essential is that each country has its own weaknesses in environmental protection. For instance, even though the industrialized countries possess advanced technology and the financial resources for environmental preservation, many of them cannot solve the serious problem of emission induced climate change because reducing this problem may slow down their industrial production and lower their people's comfort and convenience. Accordingly, nations and international organizations have their roles to play in ensuring that the rich countries fulfill their environmental obligations.