Changing Earth's Surface Worksheet Answers

Geoengineering our planet

Geoengineering possibilities illustration — An illustration of many possible geoengineering schemes for changing the planet'south climate. (Image credit: The Bipartisan Policy Center.)

Humans may have changed the Earth's climate e'er since they began using "slash and burn down" tactics to clear forests for growing crops. Only today's civilizations must deal with the industrial revolution's contribution to a warming planet and the choice of trying to reverse or balance out such climate change with new geoengineering tactics.

Geoengineering ideas typically aim to finish the warming of the World's climate by removing the greenhouse gas carbon dioxide (CO2) or by reflecting more than sunlight dorsum into space. Many mimic natural processes such as the cooling effect of volcanic eruptions or boosting the CO2-absorbing upshot of forests. But the idea of humans intentionally engineering the Earth's climate on a thou scale still attracts plenty of controversy too.

Here you can take a look at ratings for some of wildest geoengineering ideas described in a 2009 report past the U.k.'south Regal Social club. The British study has been cited in subsequently U.S. reports by the U.S. National Academy of Sciences (2010) Washington-based Bipartisan Policy Center (2011).

Cloud seeding

White clouds based on small-scale micro-droplets of moisture could reflect more than sunlight to dull down the heating of the planet. Many proposals accept suggested using ships or shipping to seed clouds with a spray of salty ocean water, or peradventure dropping a special hydrophilic (water-attracting) powder from shipping.

Bear upon: Depression to Medium. There is incertitude about producing plenty of the cloud seeding effect, and the method is largely limited to areas over oceans.

Affordability: Medium. The cost of bounding main water is low, only the deject seeding must continue almost constantly for a long menstruation of time.

Timeliness: Medium. The effect on lowering temperatures would begin inside one year. Deployment could start within years or a few decades.

Safety: Low. The cloud seeding may stop upward affecting weather patterns and sea currents. There is too the possibility of pollution of the cloud seeding uses chemicals or materials other than sea-table salt.

Air capture of CO2

artificial trees, carbon removal — Bogus trees could remove carbon dioxide from the air more efficiently than the real thing. (Paradigm credit: Establishment of Mechanical Engineers.)

Humans could capture CO2 directly from the ambient air like technologies already capture carbon from power plants. The CO2 would be absorbed past solids or alkali metal liquids before being moved to long-term deep storage underground.

Impact: High. This idea is both doable and has no limits on the size of its possible issue. It also tackles a principal cause of climate change and ocean acidification by removing CO2.

Affordability: Low. The carbon capture methods would have potentially high material and energy costs.

Timeliness: Low. Humans still need to practice more than piece of work to find cost-constructive air capture methods, and would demand time to build the infrastructure to practice the job. It would too be wearisome to reduce global temperatures.

Safety: Very high. There are few side effects.

Aerosols in the atmosphere

A British climate-cooling balloon experiment — A British climate-cooling airship experiment would take sprayed water into the atmosphere to test its result on reflecting sunlight. (Image credit: Hugh Hunt, SPICE projection)

Humans could release a wide range of tiny particles into the stratosphere to reflect sunlight back into space. That mimics the natural cooling issue of huge volcanic eruptions that toss similarly small particles high into the atmosphere. Fleets of aircraft, rockets, balloons or even huge artillery guns could do the task of delivery.

Touch: High. This is already doable and peradventure very constructive. There is also no limit to its event on global temperatures.

Affordability: High. This only requires small quantities of materials at relatively low cost.

Timeliness: High. The consequence would start to reduce temperatures within one year. Deployment would just crave years or mayhap a few decades.

Safe: Depression. Many possible side furnishings include damage to the stratospheric ozone layer, effects on high-distance clouds, and bear upon on the biological productivity of plants and animals.

Space sunday shields

Free-floating mirrors in space — A constellation of billions of mirrors gratuitous-floating at the Earth-Sun Lagrange point blocks solar radiation and cools earthly global warming. (Paradigm credit: Dan Roam.)

Huge lord's day-shields in space could reflect solar radiation abroad from Globe. Such shields would require tactics worthy of a scientific discipline fiction story arrays of thousands of mirrors, swarms of trillions of reflecting disks, a huge reflector made on the moon out of lunar glass, or a Saturn-like ring of dust particles and shepherding satellites.

Impact: High. There is no limit on its possible effects on global temperatures.

Affordability: Very low to Low. Infinite launches and operations would mean a high price for deployment and maintenance, but the methods could take a very long lifetime once deployed.

Timeliness: Very low. Humans would need several decades at the very least to put reflectors into space. The reflectors would begin to reduce global temperatures within a few years.

Condom: Medium. There would be regional climate effects, but no known biochemical furnishings on the environment.

Speed up weathering

Carbon-silicate cycle speed-up — Humans could speed up the carbon-silicate cycle that traps carbon inside solid rocks. (Image credit: J. F. Kasting | Penn Country University)

Weather condition effects naturally eat away at silicate rocks (the most common rocks on Earth) an consequence that leaves silicate gratis to react chemically with CO2 and store it as carbonate rock. The natural procedure occurs slowly over many thousands of years, but humans could speed upwardly the weathering event by mining silicate materials to spread them more widely. They could possibly even store the dissolved materials leftover by the chemical reactions in the oceans.

Impact: Loftier. There is plenty of room for storage in either the Earth's soils or oceans. Both methods would accost the cause of both climate change and sea acidification, but dumping materials in the ocean could straight reverse bounding main acidification.

Affordability: Low. The mining, processing and transportation of silicate materials would exist expensive and mayhap require a lot of energy.

Timeliness: Low. This would be slow to reduce global temperatures, would take time to build the necessary infrastructure, and would as well require fourth dimension to investigate its efficiency and possible side effects on the environment.

Safety: Medium or High. May have side effects on soil pH, vegetation, and marine life.

Brand the desert shiny

Solar reflectors in the desert — Solar reflectors similar to those used on solar farms could reflect sunlight in the desert to cool downwardly the Earth. (Image credit: Desertec-United kingdom of great britain and northern ireland.)

Hot deserts receive high levels of solar radiation through sunlight. One geoengineering proposal suggests roofing the deserts with reflective polyethylene-aluminum surfaces to boost their reflective power an thought similar to the lower-risk concept of making building rooftops white or shiny to reflect sunlight.

Bear on: Depression to Medium. This idea would crave consummate and very cogitating coverage of all major desert areas (about 10 percent of all state).

Affordability: Very depression. The cost of materials, deployment and maintenance could be huge.

Timeliness: Loftier. Could be done very quickly and would testify rapidly effective.

Safe: Very low. At that place would be huge environmental and ecological impacts on desert ecosystems, as well as probable effects on weather.

Sea fertilization

phytoplankton blooms — Phytoplankton blooms in the North Atlantic from Iceland to the shores of France in this NASA Terra satellite image. (Image credit: NASA | Jeff Schmaltz, MODIS Rapid Response Squad.)

Ocean algae floating on surface waters stand for natural sponges that soak up CO2 the showtime step toward storing CO2 in the deep sea as dead organic matter sinks to the bottom. Researchers have tried pocket-size experiments to find out if seeding the ocean with iron or other nutrients tin can heave algae blooms and that CO2 storage effect.

Impact: Low. Humans could effort this geoengineering tactic today, just tests have suggested information technology wouldn't be very effective. The ocean'southward natural carbon cycling too makes this unlikely as a long-term carbon storage solution.

Affordability: Medium. This would not be very cost-constructive, especially for methods other than iron fertilization.

Timeliness: Low or Very depression. Ocean fertilization would be slow to reduce the Earth'south global temperatures.

Safe: Very low. This method has large risks for "unintended and undesirable ecological side effects," such every bit increasing the number of ocean "expressionless zones" starved of oxygen or slightly increasing acidification of the deep bounding main.