Global warming has far-reaching impact on biodiversity and climatic conditions of the planet. Several current trends clearly demonstrate that global warming is directly impacting on rising sea levels, the melting of ice caps and significant worldwide climate changes. In short, global warming represents a fundamental threat to all living things on earth.
One way of measuring the effect of global warming can be designed by studying O-18 to O-16 isotopic ratio of the shells of marine organisms and marine sediments. When ocean-water evaporates it contains a mixture of two isotopes O-16 and O-18. Being somewhat heavier, H2O-18 condenses and falls of as rain somewhat sooner than H2O-16. Thus precipitation in oceans should be richer in H2O-18, than precipitation that proceeds further to form polar ice caps. As the world’s ice increases, this cycle operates quite effectively, selectively removing H2O-16 from the sea water and depositing them in polar ice-caps, leaving the sea water richer in H2O-18. Hence, marine organisms that build their shells out of CaCO3 in sea water will have a higher ratio of O-18 to O-16 when it is cold and lower, when it is hot. This way, just by measuring the ratio of isotopes in ocean sediments and shells, impact of global warming can be quantized and a scale can be developed accordingly.