Two scientific studies published last week indicate that the effects of climate change will have a noticeable effect on our lives by the end of this century. Both studies found that sea levels are rising much faster than previously thought.
The first study, published by an influential group of scientists led by James Hansen states that the impact of climate change will be felt much sooner and could be much more catastrophic than most of us realize. Hansen is the former NASA scientist, who is often credited with being the first scientist to drawn attention to climate change back in 1988 during his testimony to Congress.
The 52-page paper published last Tuesday, has the unwieldy title, Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 °C global warming could be dangerous. The paper was published online in the journal Atmospheric Chemistry and Physics.
According to the paper, the present goal of limiting the increase in global temperatures to 2 degrees Celsius above the preindustrial level is not enough, because the last time the Earth warmed by that much was about 120,000 years ago and the consequences were disastrous. The authors of the paper state that heat-trapping gas emissions from human activity have led to global temperature increases, which in turn have caused land ice to melt rapidly. When the land ice melts, the melted freshwater drains into the ocean and this has accelerated the melting of the ice sheets in Antarctica and Greenland. The authors of the study go on to say that this increase in cold ice melt draining into the oceans will eventually either slow down or shut off the ocean currents that redistribute heat around the world. When that happened about 120,000 years ago, sea level rose 20 to 30 feet (6 to 9 meters), and there were also violent storms powerful enough to throw giant boulders around on shore. Hansen and his 18 co-authors explain it this way.
- “First, our conclusions suggest that a target of limiting global warming to 2 degrees Celsius, which has sometimes been discussed, does not provide safety.
- Second, our study suggests that global surface air temperature, although an important diagnostic, is a flawed metric of planetary ‘health,’ because faster ice met has a cooling effect for a substantial period.
- “Third, not only do we see evidence of changes beginning to happen in the climate system, as discussed above, but we have also associated these changes with amplifying feedback processes. There is a possibility, a real danger, that we will hand young people and future generations a climate system that is practically out of their control. We conclude that the message our climate science delivers to society, policymakers, and the public alike is this: we have a global emergency.”
The second report, Contribution of Antarctica to past and future sea-level rise, was published Thursday in the scientific journal Nature. The authors of that report, Robert DeConto of the University of Massachusetts and David Pollard of Pennsylvania State University, state that the melting of the ice in Antarctica has the potential to contribute to a rise in sea levels of more than 3 feet (1 meter) by the end of this century. That would have a dramatic effect on the people who live in low lying coastal communities around the world. For example, Miami is only 5.906 feet above sea level.
The report also says that because ice is also melting in other parts of the world, seas levels could rise 5 or 6 feet (1.5 to 1.8 meters) by the end of this century, far more than predicted in a United Nations study published in 2013. According to DeConto and Pollard, by the year 2500, Antarctica could contribute to a rise in sea levels of 15 meters (50 feet). DeConto and Pollard, also say that by the middle of the next century, sea levels could rise at a rate of more than 1 foot per decade if the current rate greenhouse gas emissions continue unchanged.