Think carbon and nitrogen
Q: April 22 marks the 40th anniversary of Earth Day, the launching point for America's modern environmental movement. To what extent has the U.S. delivered on the vision of Earth Day's founders, and where has the modern environmental movement gone wrong?
The environmental movement that gained momentum from the first Earth Day resulted
in cleaner air and water, less contaminated landscapes and more conservation of vital
environments, plants and animals than would have otherwise occurred. The Clean Air Act; Clean Water Act; National Environmental Policy Act (NEPA); Comprehensive Environmental Response, Compensation and Liability Act (CERCLA); and Endangered Species Act were passed with a sense of urgency and purpose, all within a decade and with bipartisan support!
Amendments over the years have strengthened these landmark laws, but still we face environmental challenges of daunting proportions. This is not because the modern environmental movement has "gone wrong," but because the threats we now face were not adequately anticipated, partly because the rapid expansion of human activity was underestimated, and because these threats result from massive disruptions that are systemic, and even global, in proportion.
As an environmental scientist, I spend most of my time addressing threats resulting from disruption of the natural cycles of two elements that are next-door neighbors on the Periodic Table: carbon and nitrogen. Both are essential to life, so they may not be regarded as "pollutants" by many people. Human activities, particularly burning fossil fuels and clearing forests, now so dominate the carbon cycle to the point that the global atmospheric concentration of CO2 has increased by 38 percent, causing the Earth's climate to rapidly warm and the oceans to acidify. The rapid growth in use of industrial fertilizers after World War II has allowed us to feed the 6.7 billion people on the planet but, along with nitrogen oxides created by fossil fuel combustion, has overloaded the land with forms of fixed (bioavailable) nitrogen. These acidify soils and lakes and drain off to coastal waters causing dead zones in places like the Chesapeake Bay and Gulf of Mexico. Releases of N2O, a greenhouse gas more potent than CO2, are also increased.
It is now very clear that the pervasive overloading of carbon and nitrogen cycles endangers both Earth's biological riches and human society. Many human activities, including
energy, food production and transportation, contribute to these disruptions, thus requiring comprehensive and systematic approaches to their mitigation. For greenhouse gases this must be done on a global scale.
While we celebrate the many environmental accomplishments of my generation following the first Earth Day, it is imperative that we now find bold new solutions and safeguards during the generation that lies ahead. We should remember that there were those who vigorously opposed the landmark legislation of the 1970s and their subsequent amendment, arguing that it would damage the economy. But time and time again, this proved not to be the case as new technologies came about and even made profits. In the spirit of the 1970s, passage of a bipartisan, comprehensive energy and climate change legislation in 2010 would be a good start for the next generation.