Mid-summer, Northern hemisphere
Because the Earth is tilted on its axis, the length of the day (i.e. the time
between sunrise and sunset) changes throughout the year.
During summer in the northern hemisphere the North Pole is tilted
towards the Sun and days are longer and warmer, and during winter the
North Pole is tilted away from the Sun and the days are shorter and
colder.
Equinox Equinox Mid summer,
northern hemisphere
The intensity of
insolation received
at any given
latitude can be
found using
Lambert’s Law.
Also,
the amount of solar
energy lost as it
comes through our
atmospheric gases
is strongly affected
(Beer’s Law) by the
thickness of the
atmosphere
through which the
energy must pass.
Insolation (for incoming solar radiation)
Abandoned ships near fishing town Moynaq in Uzbekistan in April 2008.
The Aral Sea, a once vast brackish terminal lake in
the heart of Central Asia, has been rapidly drying
since the 1960s. It had separated into four separate
waterbodies by September 2009.
The main causative factor until the 1960s was the
periodic westward diversion of the Amu Dar’ya, the
main influent river, towards the Caspian Sea by both
natural and human forces.
The post-1960 recession, however, was
overwhelmingly the result of unsustainable irrigation
development. The lake’s modern recession has
caused a broad range of severe negative ecological,
economic and human welfare problems.
Aral Sea
August 25, 2000 August 19, 2014
His aim was to devise formulas that would define climatic
boundaries in such a way as to correspond to those of the
vegetation zones (biomes) that were being mapped for the first
time during his lifetime.
In western North America it's easier to visit several biomes than in the
East. That's because the West is more mountainous, and it's possible to
pass through various biomes simply by traveling up mountain slopes;
traveling a few hundred feet upslope is equivalent, biologically speaking,
to going north overland for hundreds of miles.
In western North America, you simply find a high mountain and climb until the trees
almost peter out. Beyond the mountain's taiga, if the slope continues, there may be
treeless tundra, very much as in the arctic.
In eastern North America, to visit taiga, which is a swampy, coniferous forests consisting
mostly of pines, spruces and larches, one must travel deep into Canada
Northern Hemisphere
tundra flowers
shrub willow plants
tiaga
tiaga
tropical rainforest
tropical deciduous forest
deciduous forest
temperate deciduous forest
Savanna and Tropical Grassland
Savanna and Tropical Grassland
temperate grasslands of native Nevada
bluegrass
temperate prairie
chaparral
chaparral
tropical thornscrub forest
tropical scrub forest
The 110MW retrofit of SaskPower’s Boundary Dam coal-fired
power plant in Saskatchewan, Canada will trap around 1
million tonnes of carbon dioxide (CO2) per year. The captured
CO2 will be injected into nearby oilfields to enhance oil
recovery. The plant began capturing CO2 in September, 2016.
Eruption of Mount Pinatubo,
Philippines, on June 15, 1991
While sulfur dioxide
released in
contemporary volcanic
eruptions has
occasionally caused
detectable global
cooling of the lower
atmosphere,
the carbon dioxide
released has never
caused detectable
global warming of the
atmosphere.
The gray bars at the top correspond to periods when Earth's climate was relatively
cool; the white spaces between them correspond to warm modes.
CO2 levels have have fluctuated from about two to four times modern levels
with a dominant period of about 100 My.
No correspondence between pCO2 and climate is evident because the evident
100 My cycle of the pCO2 record does not match the longer climatic cycle.
Feb. 18, 2015, the Great Lakes were 85.4 percent ice-covered, just above the 85.2
percent on Feb. 18 the year before, according to the Great Lakes Environmental
Research Laboratory. With below-average temperatures predicted for at least the
next week, the lakes could approach the year before levels of 92.5 percent ice
cover, the second-highest level since records began in the early 1970s.
Periodicity: 100,000 years
The seasonal cycle of insolation (Q) at 65 N latitude based
on eccentricity 100,000-year cycle, obliquity (axial tilt)
41,000-year cycle, and precession 26,000-year cycle.
The scale on
the vertical axis
is change in
O18 content.
By the work of
Lisiecki et al
2005 and
Huybers 2007,
the next
glaciation is
fully developed
between
AD 55,000 and
60,000, with
the next
interglacial
20,000 years
after that.