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[____] Warming is caused by humans – the variation of temperature increase is much higher than normal.
Stephanie B. Oshita, Assistant Professor of Environmental Science and Management at the University of San Francisco, 2007, “The Scientific and International Context for Climate Change Initiatives” 42 U.S.F.L. Rev. 1 Summer
Even if we recognize that the globe is warming, how do we know that humans are causing the phenomenon? Through a combination of measurements and models, we can discern the human "fingerprint" on the climate system in a number of ways. n27 First, the observed warming goes well beyond natural variation. Paleoclimatology - the sleuthing for indicators of past temperatures in ice cores and coral reefs - indicates that current levels of CO2 in the atmosphere far exceeded the natural range of the last 650,000 years. n28 We know that the atmospheric concentrations of CO2 and temperature are strongly correlated, explaining why temperatures levels are higher than ever before. n29 Second, the rapid increase in levels of CO2 in the atmosphere coincides with the onslaught of the industrial revolution and the release of CO2 from fossil fuels, along with dramatic changes in land use by humans. n30 Third, models of the climate system with and without human emissions show that natural variation alone cannot obtain observed [*7] changes. n31 Natural fluctuations in the Earth's orbit, natural variation in solar activity, and other non-human phenomena cannot account for the rapid rise in atmospheric greenhouse gases and average temperature over the past century. Human activity does explain the observed changes
[____] The increase of carbon dioxide in the atmosphere is very predictable, and it has increased dramatically in the last 50 years due to human activity.
Lester E. Brown, Director and Founder of the Global Institute of Environment in the U.S. and President and Senior Researcher at the Earth Policy Institute, 2008 [Lester E., “Plan B 3.0: Mobilizing to Save Civilzation”
Scientists at the Goddard Institute for Space Studies of the National Aeronautics and Space Administration (NASA) gather data from a global network of some 800 climate-monitoring stations to measure changes in the earth's average temperature. Their direct measurements go back to 1880.6 Since 1970, the earth's average temperature has risen by 0.6 degrees Celsius, or 1 degree Fahrenheit. Meteorologists note that the 23 warmest years on record have come since 1980. And the seven warmest years since recordkeeping began in 1880 have come in the last nine years. Four of these-2002, 2003, 2005, and 2006-were years in which major food-producing regions saw their crops wither in the face of record temperatures. The amount of carbon dioxide (C02) in the atmosphere has risen substantially since the start of the Industrial Revolution, growing from 277 parts per million (ppm) to 384 ppm in 2007. The annual rise in the atmospheric C02 level, one of the world's most predictable environmental trends, is the result of the annual discharge into the atmosphere of 7.5 billion tons of carbon from burning fossil fuels and 1.5 billion tons from deforestation. The current annual rise is nearly four times what it was in the 1950s, largely because of increased emissions from burning fossil fuels. As more C02 accumulates in the atmosphere, temperatures go up.
Impact – Warming Not Inevitable
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[____] Warming is not inevitable. Many of the predicted consequences can still be avoided.
James E Hansen, NASA Goddard Institute for Space Studies and Adjunct Professor in the Department of Earth and Environmental Sciences at Columbia University, 6/25/2007, “How Can We Avert Dangerous Climate Change?” Delivered to the Select Committee on Energy Independence and Global Warming, United States House of Representatives, http://arxiv.org/pdf/0706.3720
We have solved or are solving those pollution problems, at least in developed countries. But we did not address them until they hit us with full force. That approach, to wait and see and fix the problems post facto, unfortunately, will not work in the case of global climate change. On the contrary, the inertia of the climate system, the fact that much of the climate change due to gases already in the air is still ‘in the pipeline’, and the time required for economically-sensible phase-out of existing technologies together have a profound implication. They imply that ignoring the climate problem at this time, for even another decade, would serve to lock in future catastrophic climatic change and impacts that will unfold during the remainder of this century and beyond (references A and B). Yet this is not a reason for gloom and doom. On the contrary, there are many bright sides to the conclusion that the ‘dangerous’ level of CO2 is no more than 450 ppm, and likely much less than that. It means that we, humanity, are forced to find a way to limit atmospheric CO2 more stringently than has generally been assumed. In so doing, many consequences of high CO2 that were considered inevitable can be avoided. We will be able to avoid acidification of the ocean with its destruction of coral reefs and other ocean life, retain Arctic ice, limit species extinctions, prevent the U.S. West from become intolerably hot, and avoid other undesirable consequences of large global warming. It is becoming clear that we must make a choice. We can resolve to move rapidly to the next phase of the industrial revolution, and in so doing help restore wonders of the natural world, of creation, while maintaining and expanding benefits of advanced technology. Or we can continue to ignore the problem, creating a different planet, with eventual chaos for much of humanity as well as the other creatures on the planet.
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