$200 is a bit low. I'm not sure you'd be entirely happy with either one.
"Sandstorms inflict damage of about $540 million per year, and losses of crops and forests due to acid rain amount to about $730 million per year. More serious are the $6 billion costs of the "green wall" of trees being built to shield Beijing against sand and dust, and the $7 billion per year of losses created by pest species. We enter the zone of impressive numbers when we consider the onetime cost of the 1996 floods ($27 billion, but still cheaper than the 1998 floods), the annual direct losses due to desertification ($42 billion), and the annual losses due to water and air pollution ($54 billion). The combination of the latter two items alone costs China the equivalent of 14% of its GDP each year." - Jared Diamond, Collapse: How Societies Choose to Fail or Succeed