I am an atmospheric scientist and a professor at University of Illinois in Urbana-Champaign. Climate change is one of the important issues facing humanity and, as Sir David King, science adviser to two UK prime ministers, has said, it may be "the biggest challenge of all time." It is important to realize that climate change and its impacts are about science and not politics. Its existence does relate to past human choices. Policy and politics do come into play when we determine what to do about it.
Climate is the long-term averages and variations in weather. The science is clear – our climate is changing, and it is changing extremely rapidly, about 10 times more rapidly than nature tends to change the climate worldwide. Many aspects of the climate globally and in the United States, including here in Illinois, are changing. Many thousands of observational-based studies have documented the increasing surface, atmospheric and oceanic temperatures on climate time scales. Observations also show many other aspects of a changing climate, e.g., that the vast majority of glaciers, including much of Greenland and Antarctica, are melting, snow cover is diminishing, sea ice is shrinking, sea levels are rising and our oceans are acidifying. In addition, water vapor in the atmosphere is generally increasing – basic physics tells us that a warmer atmosphere can hold more water vapor. And this increase in water vapor should lead to larger precipitation events, which is also observed.
Climate change is affecting all of us – it is not just about it being warmer; climate change is also leading to more extreme weather, more intense wildfires, more intense storms and reductions in coastlines from rising sea levels. These are already affecting our infrastructure, our lifestyles, and sometimes, human lives. The frequency, size and duration of extreme heat events have increased. Multi-day heat waves are occurring about three times more often now than they did 50 years ago. Due to changes in weather patterns, some regions are seeing an increasing risk for drought, while others see an increasing tendency for floods. When it does rain or snow, it is more likely to be a larger event than in the past.
Evidence continues to mount that large storms like hurricanes are growing stronger and more destructive. These storms are producing heavier rain; their storm surges are riding atop higher sea levels. In some cases, they are lingering longer over land, causing increased flooding and infrastructure destruction.
Humans have long witnessed natural disasters, but now we are seeing an increasing intensity of such events. What were once very rare events are now becoming more common. The science shows that these increases in unnatural disasters are happening because of our changing climate. The changing climate will have even larger impacts as these changes and resulting impacts become larger over the next few decades.
Scientists have long been studying these changes to our climate and to severe events and the factors driving these changes. The evidence clearly shows that human activities have been driving the changes in our climate, especially as a result of emissions of carbon dioxide and other gases and particles from the use and burning of fossil fuels, and also from land use change. An examination of the peer-reviewed science shows that there is essentially no debate in the science community – this understanding is based on an extensive number of measurements and associated analyses using many different research tools.
Without action to slow down these changes, climate-related risks will continue to grow. We need to stop acting as if climate change is a political issue. This is an important issue that is affecting all of the people and other life on our planet. The real debate should be how we find the right solutions to climate change and make sure we leave a legacy of hope for our children and grandchildren.
Being part of the Paris Agreement, the so far voluntary effort, enables the United States to provide leadership in getting all countries to work with us in reducing the emissions that affect future changes in climate. This means transitioning our energy and transportation sectors, while continuing to build our economy, to eventually eliminate human-related emissions that drive the changes in climate. We need to emphasize the development of pathways and technologies that will allow us to make that transition. The use of solar and other renewable sources of energy are continuing to increase and these are having a positive impact on our economy. Reducing emissions while not hurting jobs or the economy will be important. We also need to emphasize making our communities, our cities and our industries more climate-resilient even while we try to slow down future changes in climate.
As a Rotarian, the four-way test is an important part of my life. The science shows that climate change is the truth. We need to ensure solutions that are fair to all, build good will and better friendships, and are beneficial to all.
Donald Wuebbles is the Harry E. Preble Professor of Atmospheric Science at the University of Illinois. He recently gave an invited presentation to the University of Illinois Springfield and the World Affairs Council of Central Illinois on this topic.