Is There a Connection Between Global Warming and Natural Disasters?

This is a topic that I have heard a lot about before I found an article pertaining to it. And to be completely honest, this is something that I have really wanted to know. I think that everyone has noticed that there have been more droughts, floods, hurricanes, and tornadoes in the last couple years. And the popular question to this is, "Why? Why have there been so many more hurricanes and tornadoes now more than ever?" Well, the article 'Extreme Weather Research Makeover' starts to investigate that question. The journalist who wrote this, Sarah Kuck, starts the article out by stating that a group of scientists that specialize in climate have formed the coalition ACE, Attribution of Climate-Related Events. What this coalition is trying to answer is if there is a connection between the increased number and severity of hurricanes, tornadoes, floods, and droughts. Kuck goes on to explain that, 'In 2010, extreme heat waves caused massive wildfires in Russia, while heavy monsoon rains brought severe floods in Pakistan. The global average temperature was one of the highest since records began in 188o, according to the U.S. National Oceanic and Atmospheric Administration," Kuck continues this statement by saying that, "Previously, scientists have said that an increase in extreme weather events like these would be consistent with global warming but were hesitant to make a direct link between specific events and climate change because of the natural variability of weather".

I really do not understand why the scientists, who have previously stated that if there was an increase in these intense weather conditions, are not making a connecting these two together. I realize that there is a 'natural variability of weather', but if that is what they were so sure about before what made them change their thoughts?

"The ACE coalition asserts that it is now possible to prove that greenhouse gases, resulting in observable increase in atmospheric moisture, are causing extreme weather events," Kuck explains. It seems like while the members of ACE think that global warming is what is causing these severe weather issues. However, it seems like the scientists that they are trying to work with don't agree with that. Dr. Kevin Trenberth thinks that the evidence of the links that are between these severe weather problems and climate change are 'unequivocal'.  He has also told them that the only things to really focus on are changes in rainfall, heat waves, drought, flooding, and other severities like hurricanes and tornadoes. "All weather and climate events are affected by climate change because the environment in which they form is different,” wrote Trenberth. “The failure to realize this means that the cost of climate change is greatly underestimated".