Page 7 - ClimatChange-GB
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FOREWORDA Daunting ChallengeGlobal warming is incontrovertible and unprecedented in the last thousand years. The greenhouse effect is increasing at a fast rate, the average temperature is growing, and the sea level is rising at 3mm per year.Climate change is a reality, with impacts that can be seen world-wide. Satellites provide the data that allows scientists to con rmthe degree of change and to track its impact. The data being deliveredby satellites like Cryosat, Meteosat, Jason, SMOS and many others,whether concerning melting ice, the temperature and levels of theoceans, or soil humidity, exceeds even the most alarmist forecasts.Since the beginning of the industrial era, the average global surfacetemperature has risen by about 0.6° Celsius. In addition, the currentlevel of carbon gas emissions is the highest ever recorded. If we are to remain under the threshold of a 2°C rise, we have to limit consumption and no longer release more than one trillion ton of C02, while still unexploited fossil fuel reserves contain  ve trillion tons.With a rise of 2°, we can perhaps still adapt to global warming. But if this increase reaches 4° by the end of the century, the consequences could be disastrous.We face a daunting challenge, one that implies abandoning our current development-focused society and transitioning to a more carbon-stingy model. Solutions do exist – energy ef ciency, renewable energies – but they have to be deployed without further ado. We also have to work together to implement attenuation and adaptation policies.The political objective set by the United Nations Framework Convention on Climate Change (UNFCCC), of limiting the temperature rise to 2°C, gives reason for hope – if all countries un- derstand the urgency of this goal and what's at stake. A  rst victory would be meeting the goal promoted by Europe, of a 40% worldwide reduction in greenhouse gases by 2030.The COP21 UN Climate Change Conference, if it results in suf ciently ambitious agreements, can also play a fundamental role in achieving this goal.No matter what happens, we all have to marshal our forces. We must pursue our research efforts, develop new observation and research tools, and re ne our climate models to plug gaps and reduce areas of uncertainty. It is also vital that we evaluate to what degree the environment, business activities, and society as a whole are exposed to climate change. Satellites play a key two-pronged role in meeting this challenge: they deliver vital data, and also remind us, from their spot in the hostile environment that surrounds us, of the  nite nature and fragility of our planet.Jean Jouzel, IPCC Bureau Member, Research Director at the CEA


































































































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