When enough evidence of global warming?

It has been hard to know what to think about global warming. Since Al Gore first warned of a changing climate, we have seen scores of research that suggests indeed the planet is getting warmer, and other research suggesting recent changes are anomalies. We shouldn’t have to wonder any more. According to both NASA and the National Oceanic and Atmospheric Association, 2016 was the warmest year ever in North America. The previous warmest years were in 2015 and 2014. That makes three years in a row scientists have documented the warming of our planet. The top five hottest years have all come this century. Much of the warming is attributed to greenhouse gases like carbon dioxide which trap heat in the atmosphere, although an El Nino also contributed to the warmer temperatures. Despite the mounting evidence of a warming planet, some refuse to believe our climate is changing, much less who or what is to blame. How much more evidence do we need? Three straight years of global warming apparently isn’t enough for some. Do we need to see four straight years? Five? Should we wait 10 more years before we make up our mind and finally decide to do something about it? By then, it may be too late.