Page 148 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

and Surface Energy Budgets THEhumanDENOMINATOR 4 Changes in Atmospheric
ENERGY BALANCE HUMANS
• The Earth–atmosphere system balances itself naturally, maintaining planetary systems that support Earth, life, and human society, although the steady-state equilibrium appears to be changing.
• Solar energy is harnessed for power production worldwide by technology ranging from small solar cookers to large-scale photovoltaic arrays.
HUMANS ENERGY BALANCE
• Thawing of Arctic sea ice illustrates albedo and temperature effects of human-caused climate change.
• Aerosols and other particulates affect the energy budget and have both cooling and warming effects on climate.
• Fossil fuel burning produces carbon dioxide and other greenhouse gases that force warming of the lower atmosphere.
• Urban heat island effects accelerate warming in cities, which house more than half the global human population.
4a
NASA scientists collect data from U.S. Coast Guard platforms in the Atlantic Ocean. Although oceans cover 70% of Earth’s surface, scientists have limited knowledge of the oceans’ role in the Earth–atmosphere heat balance. [S. Smith/(closeup) NASA Langley Research Center.]
The International Maritime Organization, made up of
170 countries, is developing policies to reduce diesel ship emissions, especially black carbon. In 2015, improved energy-efficiency standards
will be enforced for construction of all large ships.
4b
[Justin Kasezninez/Alamy.]
4d
18 16 14 12 10
8 6
4 2
Solar energy drives Earth systems,
including winds, ocean currents, weather,
and living ecosystems. [NASA/JSC.]
Arctic Sea Ice Extent
(area of ocean with at least 15% sea ice)
2012
2007
1981–2010 average 1979–2000 average
4e
Urban surfaces absorb more radiation than natural surfaces, adding to increased temperatures in urban heat islands. Increased use of lighter- coloured pavement lowers surface albedo, reducing this effect. [Arizona State University National Center of Excellence on SMART Innovations.]
Jan Feb
Mar
April
May
June July
Aug Sept Oct
Nov Dec
4c
The Gujarat Solar Park in western India covers 1214 hectares and
is one of the world’s largest photovoltaic solar facilities. The park reached a capacity of
500 MW in 2014.
[Ajit Solanki/AP Images.]
Arctic sea ice reached its lowest extent on record in 2012. Continued loss of summer ice will exacerbate the positive feedback loop between lower albedo, ice melt, and atmospheric warming. [Courtesy National Snow and Ice Data Center.]
ISSUES FOR THE 21ST CENTURY
• Continuing albedo effects associated with melting sea ice and aerosols will hasten air- and ocean-warming trends.
• Increased burning of fossil fuels will add more greenhouse gases. Solar energy can offset fossil fuel use.
• Continuing urbanization will worsen heat-island effects and contribute to the general warming trend.
geosystemsconnection
We tracked the inputs of insolation, followed the cascade of energy through the atmosphere to Earth’s surface, and examined the resulting movements and processes. We ended this journey from Sun to Earth by analyzing the distribution of energy at the surface and the concepts of energy bal- ance and net radiation. in the next two chapters, we shift our focus to other outputs in the energy– atmosphere system—the results and consequences of global temperature patterns, and the wind and ocean current circulations driven by these flows of energy.
Extent (millions of square kilometres)
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