Context This lesson was developed by Dr. Penny Firth, a scientist, as part of a set of interdisciplinary Science NetLinks lessons aimed at improved understanding of environmental phenomena and events. Some of the lessons integrate topics that cross biological, ecological, and physical concepts.
Human sources of nitrogen may be just as environmentally costly as carbon emissions. Transcript The perils of excess nitrogen. I'm Bob Hirshon and this is Science Update. It's no secret that human carbon emissions are a big problem.
But two recent reviews in the journal Science warn that we also need to curb our production of reactive nitrogen. University of Virginia bio-geochemist James Galloway notes that inhumans produced roughly twice as much reactive nitrogen as nature did—mainly by farming with nitrogen-packed fertilizers and burning fossil fuels.
And so as this reactive nitrogen is lost, it cycles throughout the earth's reservoirs—soils, waters, and the atmosphere, As it moves through these reservoirs, it causes these cascades of environmental impacts. Impacts that include air pollution, acidic soil and water, ozone depletion, and global warming—and the resulting threats to animals and people.
Making Sense of the Research Carbon emissions have been dominating the headlines lately, and there's a lot of interest in trying to control them.
But recent scientific reports suggest that we're ignoring an equally large problem: In fact, it makes up 78 percent of the air you breathe, and about 3 percent of your body. However, the nitrogen in the air is actually molecular nitrogen, or N2which is inert.
In other words, it doesn't react chemically with anything else. Galloway and his colleagues are concerned about reactive nitrogen, which comes from two main sources: All plants need reactive nitrogen to grow, and it takes lots of nitrogen-rich fertilizer to grow a farm full of crops.
However, only about 50 percent of the nitrogen in fertilizers gets absorbed by crops, and only 10 to 15 percent ultimately gets consumed by people. The rest ends up washing out of the soils and into streams and rivers that ultimately carry it out to the ocean.
Even the nitrogen that humans do eat gets back into the environment through the human waste in our sewage. What's more, a single reactive nitrogen atom can pass from the air to the soil to the water, wreaking havoc every step of the way. For example, a nitrogen atom that's released from factory smoke may start by forming smog in the air.
If rain flushes that same atom out of the air, it can end up in lakes and forest soils as nitric acid, which can kill fish and insects. From there, the nitrogen atom could be carried out to the coast and contribute to environmental problems like red tides and dead zones. When the algae die, they sink to the sea floor and are eaten by bacteria, which consume excess oxygen that fish and other marine life need to survive.
After contributing to that damage, that same nitrogen atom can evaporate back into the atmosphere as part of the greenhouse gas nitrous oxide, which destroys the atmospheric ozone layer that protects us from harmful ultraviolet radiation.
Cutting back industrial emissions is challenging enough, but cutting back food production is virtually impossible: Doing so will take a lot more study and a concerted effort by farmers around the globe.
Now try and answer these questions: What is the difference between reactive nitrogen and inert nitrogen? What are some of the dangers posed by reactive nitrogen? What are the main sources of reactive nitrogen from human activities?
In what other days has the increasing standard of living of the human species come into conflict with long-term sustainability?
You may want to check out the June 6,Science Update Podcast to hear further information about this Science Update and the other programs for that week.
This podcast's topics include: CO2's dangerous overlooked cousin, the origins of the southern hemisphere, why magnetic credit cards don't stick to the fridge, and why so many white cats are deaf.
In the National Geographic lesson plan Making the Grade: Health Indicators in the Chesapeake Bay Watershed students use online tools and resources to examine data concerning key indicators of the health of the Chesapeake Bay watershed and the factors that affect them, including nitrogen-rich agricultural runoff.Plastic Pollution Lesson Plan.
Thank you for supporting the ocean by celebrating World Oceans Day! This lesson was designed with youth in mind and we hope that young people will use this resource to teach their peers and community members about plastic pollution, inspire them with solutions, and empower them by doing an activity.
Disclaimer Yes! By submitting this form I ask to receive email, texts and calls about degree programs on behalf of Concordia University - Portland, and agree automated technology may be used to dial the number(s) I provided. (Created on 16/01/) FACTS: Water pollution "is the contamination of water bodies (e.g.
lakes, rivers, oceans, aquifers and groundwater).This form of environmental degradation occurs when pollutants are directly or indirectly discharged into water bodies without adequate treatment to remove harmful compounds.
Water pollution affects the entire biosphere – plants and organisms living in. Global Warming Lesson. Air -The Search for One Clean Breath. Page 1 Ventura County Air Pollution Control District, Ventura, CA EFFECTS OF GLOBAL WARMING.
Following a Lesson on Pollution, students should know the information well enough to help control pollution problems and be able to inform others on the issues of Pollution. Lesson Activities: (45 min. class). Find an array of environmental and science based lesson plans, activities and ideas below from EPA, other federal agencies and external organizations.
Encontrar recursos para estudiantes y maestros. You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to.