The Great Global Warming Hoax?
Pacific decadal oscillation to The ocean and atmosphere can work together to spontaneously generate internal climate variability that can persist for years to decades at a time.
For example, alterations to ocean processes such as thermohaline circulation play a key role in redistributing heat in the world's oceans. Due to the long timescales the global warming reader a century of writing about climate change this circulation, ocean temperature at depth is still adjusting to effects of the Little Ice Age  which occurred between the and s.
A schematic of modern thermohaline circulation. Tens of millions of years ago, continental-plate movement formed a land-free gap around Antarctica, allowing the formation of the ACCwhich keeps warm waters away from Antarctica. Life Life affects climate through its role in the carbon and water cycles and through such mechanisms as albedoevapotranspirationcloud formationand weathering.
Variations in CO2temperature and dust from the Vostok ice core over the lastyears Human influences Main article: Global warming In the context of climate variation, anthropogenic factors are human activities which affect the climate.
The scientific consensus on climate change is "that climate is changing and that these changes are in large part caused by human activities",  and it "is largely irreversible". While much remains to be learned, the core phenomenon, scientific questions, and hypotheses have been examined thoroughly and have stood firm in the face of serious scientific debate and careful evaluation of alternative explanations.
This is due to emissions from fossil fuel combustion, followed by aerosols particulate matter in the atmosphereand the CO2 released by cement manufacture. Milankovitch cycles Slight variations in Earth's motion lead to changes in the seasonal distribution of sunlight reaching the Earth's surface and how it is distributed across the globe.
There is very little change to the area-averaged annually averaged sunshine; but there can be strong changes in the geographical and seasonal distribution. The three types of kinematic change are variations in Earth's eccentricitychanges in the tilt angle of Earth's axis of rotationand precession of Earth's axis.
Combined together, these produce Milankovitch cycles which affect climate and are notable for their correlation to glacial and interglacial periods their correlation with the advance and retreat of the Sahara and for their appearance in the stratigraphic record.
Upon seawater temperature change, the solubility of CO2 in the oceans changed, as well as other factors affecting air-sea CO2 exchange. The period of extraordinarily few sunspots in the late 17th century was the Maunder minimum.
The Sun is the predominant source of energy input to the Earth. Other sources include geothermal energy from the Earth's core, tidal energy from the Moon and heat from the decay of radioactive compounds.
Both long- and short-term variations in solar intensity are known to affect global climate. However, there is evidence for the presence of water on the early Earth, in the Hadean   and Archean   eons, leading to what is known as the faint young Sun paradox.
The Great Oxygenation Event —oxygenation of the atmosphere around 2. Over the next five billion years from the present, the Sun's ultimate death as it becomes a red giant and then a white dwarf will have large effects on climate, with the red giant phase possibly ending any life on Earth that survives until that time.
Values since not shown. Solar output varies on shorter time scales, including the year solar cycle  and longer-term modulations. The cyclical nature of the Sun's energy output is not yet fully understood; it differs from the very slow change that is happening within the Sun as it ages and evolves.
Some studies point toward solar radiation increases from cyclical sunspot activity affecting global warming, and climate may be influenced by the sum of all effects solar variation, anthropogenic radiative forcingsetc.
The next step is to find more about these trace vapours, including whether they are of natural or human origin. The eruptions considered to be large enough to affect the Earth's climate on a scale of more than 1 year are the ones that inject overtons of SO2 into the stratosphere. The eruption of Mount Pinatubo inthe second largest terrestrial eruption of the 20th century, affected the climate substantially, subsequently global temperatures decreased by about 0.
However, because smaller eruptions occur at a much higher frequency, they too significantly affect Earth's atmosphere. In climate modelling the aim is to study the physical mechanisms and feedbacks of volcanic forcing.
Over very long geological time periods, they release carbon dioxide from the Earth's crust and mantle, counteracting the uptake by sedimentary rocks and other geological carbon dioxide sinks.
The US Geological Survey estimates are that volcanic emissions are at a much lower level than the effects of current human activities, which generate — times the amount of carbon dioxide emitted by volcanoes.
The annual amount put out by human activities may be greater than the amount released by supererruptionsthe most recent of which was the Toba eruption in Indonesia 74, years ago. Plate tectonics Over the course of millions of years, the motion of tectonic plates reconfigures global land and ocean areas and generates topography.
This can affect both global and local patterns of climate and atmosphere-ocean circulation. The locations of the seas are important in controlling the transfer of heat and moisture across the globe, and therefore, in determining global climate.
A recent example of tectonic control on ocean circulation is the formation of the Isthmus of Panama about 5 million years ago, which shut off direct mixing between the Atlantic and Pacific Oceans.
This strongly affected the ocean dynamics of what is now the Gulf Stream and may have led to Northern Hemisphere ice cover.The Global Warming Reader: A Century of Writing About Climate Change - Kindle edition by Bill McKibben. Download it once and read it on your Kindle device, PC, phones or tablets.
Use features like bookmarks, note taking and highlighting while reading The Global Warming Reader: A Century of Writing About Climate Change/5(25).
The Earth warmed by an average of ± °C during the twentieth century . Rapid warming has been measured with global instrumental data since the s (Figure 2). The Global Warming Reader A Century Of Writing About Climate Change Epub Book Epub Book The Global Warming Reader A Century Of Writing About Climate Change.
Dr David Evans, 27 June , David Evans’ Notch-Delay Solar Theory and Model Home.
If the Sun mainly controls the temperature on Earth, a turning point is almost upon us. (In the second part of this series of blog posts we will demonstrate that carbon dioxide is responsible for less than 25% of the global warming of the last six decades, so presumably the Sun is mainly responsible.).
The Global Warming Reader is a comprehensive resource, expertly edited by someone who lives and breathes this defining issue of our time. About The Global Warming Reader Van Jones, Al Gore, Elizabeth Kolbert, Naomi Klein, and other essential voices on global warming, from its 19th-century discovery to the present, in a volume edited by Bill.
With the rise of extreme weather events worldwide--witness the devastation wrought by Hurricanes Sandy, Irene, and Katrina, and the sustained drought across the American West--global warming has become increasingly difficult to deny.