Monday, July 4, 2011

The Environment: Getting Better Over Time

I have just finished reading Steven F. Hayward’s 2011 Almanac of Environmental Trends which is the latest adaption of the former Index of Leading Environmental Indicators. The book is a quick read because Dr. Hayward loves charts and data in this particular effort so that there are a limited number of words. This annual publication can be relied upon to reframe several environmental issues by simply looking at the data differently. Also, Dr. Hayward in examining the trends over the past several decades seems to mirror some of my own optimism when it comes to environment. I was working in the environmental field in the 1970’s so I always see the vast improvement in the environment everywhere I look despite the huge increase in population since that time.

The water quality section has been vastly expanded to examine the data relating to the adequacy of water supplies and the health of several estuaries including the Chesapeake Bay estuary. The good news about water is that “on average” the United States uses less than 8% of the water that falls as precipitation within our borders annually. The happy perspective of Dr. Hayward is that water like solar energy is a renewable resource and that is mostly true. Unfortunately, precipitation varies from the average significantly on a regional basis and thus, allocations and supply on a regional basis will remain a problem especially in locations where irrigations is the major water use (mostly the western states). In addition, it is unknown in most locations if we are using groundwater in a sustainable way. Comprehensive data on groundwater use for the nation is not available. There is no monitoring of groundwater basins.

For example, in California a significant portion of the water supply comes from groundwater. Typically, groundwater supplies about 30% of California’s urban and agricultural uses. In dry years, groundwater use increases to about 40% statewide and 60% or more in some agricultural regions. This rate of groundwater use is unsustainable; California is mining its groundwater, using it at a rate higher than can be recharged. When you withdraw the groundwater from fine-grained compressible confining beds of sediments and do not replace it, the land subsides. The incredibly fertile Central Valley has been identified as the location of maximum subsidence in the United States. Once the land subsides, it looses its water holding capacity and will never recover as an aquifer. The groundwater in California may be a relic of the last ice age and is not being replaced or likely to be replaced under the current climate conditions.

The three estuaries covered in this year’s edition of the Almanac of Environmental Trends are the Gulf Delta, the Long Island Sound and the Chesapeake Bay. Unfortunately, the environmental report card for the estuaries is mixed. The bottom line with the Gulf of Mexico is that hypoxia, oxygen depletion; detrimental to aquatic life has been increasing. Dr. Hayward attributes this in part to incentives in the “well-meaning but ill-designed subsidy and conservation programs…especially subsidies for ethanol related corn production.”
The data after the Gulf oil spill is not included in the series so that the hypoxia can not be attributed to that.

Long Island Sound has shown a steady progress in habitat restoration, increased wetlands and an early achievement of the 2011 fish passageway restoration goals. The combined efforts of state and local governments with conservation organizations have made much progress but are still short of the regional goal. As for the Chesapeake Bay, according to the indices created by the Chesapeake Bay Foundation, The Chesapeake Bay Program and Chesapeake EcoCheck, there has been little if any progress in the past decade after making excellent progress during the previous 22 years. Dr. Hayward, always the optimist points out that while the population in the region exploded in the past decade, the health of the Bay got no worse, still, the Chesapeake Bay Foundation judges the Bay to be “dangerously out of balance.” Hopefully the various Watershed Implementation Plans from the six states and Washington DC will show great progress in the next decade. An interesting correlation in nitrogen and phosphorus contamination in the Bay is with rainfall as seen above. I had not appreciated how much nutrient contamination was correlated with runoff volume. Riparian buffer restoration and nutrient management improvements may be our most effective methods of meeting the Chesapeake Bay TMDLs.

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