Posts tagged drought

Greenhouse gases – a public health threat

This just in from the EPA:

EPA Finds Greenhouse Gases Pose Threat to Public Health, Welfare

 

Proposed Finding Comes in Response to 2007 Supreme Court Ruling

 

 

 

(Washington, D.C. – April 17, 2009)  After a thorough scientific review ordered in 2007 by the U.S. Supreme Court, the Environmental Protection Agency issued a proposed finding Friday that greenhouse gases contribute to air pollution that may endanger public health or welfare.

 

The proposed finding, which now moves to a public comment period, identified six greenhouse gases that pose a potential threat.

 

“This finding confirms that greenhouse gas pollution is a serious problem now and for future generations.  Fortunately, it follows President Obama’s call for a low carbon economy and strong leadership in Congress on clean energy and climate legislation,” said Administrator Lisa P. Jackson. “This pollution problem has a solution – one that will create millions of green jobs and end our country’s dependence on foreign oil.”

 

As the proposed endangerment finding states, “In both magnitude and probability, climate change is an enormous problem.  The greenhouse gases that are responsible for it endanger public health and welfare within the meaning of the Clean Air Act.”

 

EPA’s proposed endangerment finding is based on rigorous, peer-reviewed scientific analysis of six gases – carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride – that have been the subject of intensive analysis by scientists around the world. The science clearly shows that concentrations of these gases are at unprecedented levels as a result of human emissions, and these high levels are very likely the cause of the increase in average temperatures and other changes in our climate.

 

The scientific analysis also confirms that climate change impacts human health in several ways. Findings from a recent EPA study titled “Assessment of the Impacts of Global Change on Regional U.S. Air Quality: A Synthesis of Climate Change Impacts on Ground-Level Ozone,” for example, suggest that climate change may lead to higher concentrations of ground-level ozone, a harmful pollutant. Additional impacts of climate change include, but are not limited to:

 

·         increased drought;

·         more heavy downpours and flooding;

·         more frequent and intense heat waves and wildfires;

·         greater sea level rise;

·         more intense storms; and

·         harm to water resources, agriculture, wildlife and ecosystems.

 

In proposing the finding, Administrator Jackson also took into account the disproportionate impact climate change has on the health of certain segments of the population, such as the poor, the very young, the elderly, those already in poor health, the disabled, those living alone and/or indigenous populations dependent on one or a few resources.

 

In addition to threatening human health, the analysis finds that climate change also has serious national security implications. Consistent with this proposed finding, in 2007, 11 retired U.S. generals and admirals signed a report from the Center for a New American Security stating that climate change “presents significant national security challenges for the United States.” Escalating violence in destabilized regions can be incited and fomented by an increasing scarcity of resources – including water. This lack of resources, driven by climate change patterns, then drives massive migration to more stabilized regions of the world.

  

The proposed endangerment finding now enters the public comment period, which is the next step in the deliberative process EPA must undertake before issuing final findings. Today’s proposed finding does not include any proposed regulations. Before taking any steps to reduce greenhouse gases under the Clean Air Act, EPA would conduct an appropriate process and consider stakeholder input.  Notwithstanding this required regulatory process, both President Obama and Administrator Jackson have repeatedly indicated their preference for comprehensive legislation to address this issue and create the framework for a clean energy economy.

 

More information:  http://epa.gov/climatechange/endangerment.html

 

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Overseeding lawns

Richard Jauron, Horticulture Specialist at Iowa State University Extension, offers the following on overseeding lawns:

Healthy, well maintained lawns are attractive landscape additions.  Lawns in poor condition, however, are somewhat unsightly.  The poor condition of a lawn may be due to poor management, heat, drought, diseases, insects or other factors.  In severe cases, the existing lawn may have to be destroyed and a new one established on the site.  Lawns that contain over 50 percent desirable grasses can often be improved by overseeding.  

Overseeding is the sowing of grass seed into an existing lawn.  In Iowa, the best time to overseed a lawn is late summer (late August to mid-September).

Site Preparation

Good site preparation is necessary for successful overseeding.  If possible, identify and correct the problems causing the lawn to decline.  Overseeding may only be a temporary solution if these problems are not corrected. 

To reduce the competition from the established turfgrass, mow the lawn at a height of 1-1/2 to 2 inches.  Successful overseeding also requires good seed-to-soil contact.  Simply throwing or broadcasting seed over the lawn typically results in poor seed germination as much of the seed is resting on the thatch layer or soil surface.  Rakes, core aerators, vertical mowers, and slit seeders can be used to ensure good seed-to-soil contact. 

Overseeding Small Areas

Small areas can be prepared by gently raking the thin spots.  When raking, it’s necessary to break the soil surface without pulling out the existing turfgrass.  After raking, sow the seed by hand.  Then, work the seed into the soil by gently raking the areas a second time. 

Overseeding Large Areas

Large areas can be prepared by using a core aerator.  Core aerators are machines with hollow metal tubes or tines.  They remove plugs of soil when run over the lawn.  To prepare the site, go over the lawn three or four times with the core aerator.  When finished, there should be 20 to 40 holes per square foot.  Apply the seed with a drop seeder.  Afterward, drag the area with a piece of chain link fence or drag mat to break up the soil cores and mix the seed into the soil. 

It’s also possible to prepare the site with a vertical mower.  When run over the lawn, the knife-like blades of the vertical mower slice through the thatch and penetrate into the upper 1/4 to 1/2 inch of soil.  One or two passes should be sufficient.  Afterwards, remove any dislodged debris from the lawn.  Sow grass seed over the lawn with a drop seeder.  Work the seed into the soil by again going over the site with the vertical mower. 

Large areas also can be overseeded with a slit seeder.  A slit seeder makes small grooves in the soil and deposits the seed directly into the slits. 

Core aerators, vertical mowers and slit seeders can be rented at many garden centers and rental agencies.  If you would rather not do the work yourself, many professional lawn care companies can overseed your lawn. 

Post Seeding Care

Keep the seedbed moist with frequent, light applications of water.  It’s usually necessary to water at least once or twice a day.  Continue to mow the lawn at a height of 1-1/2 to 2 inches.  Mow the lawn frequently to reduce the competition from the established turfgrass.  When the new seedlings reach a height of 1-1/2 to 2 inches, gradually increase the mowing height over the next several weeks.  The final mowing height should be 2-1/2 to 3 inches.  Approximately six weeks after germination, fertilize the lawn by applying 1 pound of actual nitrogen per 1,000 square feet.  

When properly overseeded, a thin, scruffy-looking lawn can be turned into a thick, lush lawn in just a few weeks. 

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