its called using science. we can track temperatures at least 10 thousand years accurately.
ice core samples for example can be used to estimate prior temperatures. using radiocarbon analysis is used, as are sediments in river beds.
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fyi, weather prediction such as this season's rainfall is not similar to current and past temperature analysis. one is taking a guess, the other is data analysis. and weather =/= climate.
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if we as a world dont make changes, it will affect how our children live. you may be of the older generation. kids are very concerned.
i also suspect you are wrong about people not willing to make sacrifices.
80% of people surveyed are willing to make changes, based on this survey:
Citizens offer mixed reviews of how their societies have responded to climate change, and many question the efficacy of international efforts to stave off a global environmental crisis.
www.pewresearch.org
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we are still the #2 emitter of greenhouse gasses. if we make a change, it will make a difference and may shame china in to doing something.
if you dont know anything about china, or chinese culture, just know that disgrace and shame - losing face - are one of the primary drivers of chinese culture. if it is seen that the rest of the world is doing its part on climate change, China will act/react.