Johanna Hoffman, a member of our Emerging Fellows program assumes that global climate will be warmer and its consequences increasingly extreme in 2050. The views expressed are those of the author and not necessarily those of the APF or its other members.
Over the last quarter century, climate change impacts have grown in scope and scale. Global temperatures rose by two degrees Celsius since the 19th century, a tremendous change given the amount of energy it takes to raise earth’s average surface temperature even a small amount. The seemingly small increase has resulted in drastic effects, from more horrific hurricanes to hotter temperatures to wildfires more destructive than anything recorded history has seen. How these shifts will play out over time is something beyond predictive capability - there are too many influencing events and inputs beyond our control. Even with the best research and foresight techniques, conditions will change in ways we can’t fully anticipate.
Despite that uncertainty, there are a few emergent trends on which scientists increasingly agree. For starters, global temperatures will continue to rise. Cities like New York will soon have dramatically longer and hotter summers, with the number of days above 32 degrees Celsius slated to more than double by 2050. In a region like metropolitan New York, where hot weather comes with significant humidity, such high temperatures over prolonged periods will result not just in serious impacts to human health and well being, but also damage to the essential myriad systems that rely on ambient air cooling, like HVAC systems and electrical grids. CO2 levels associated with those kinds of temperature increases could easily range from 550 to 600pm, up from the roughly 420ppm levels of today. Those amounts of CO2 would directly result in decreased nutrient levels in agricultural production, spikes in pollution related deaths, and widespread slowing of human cognitive function.
Hotter temperatures will also lead to rising seas. Sea levels are likely to rise at least 38cm within the next thirty years, with those numbers quite possibly reaching 100cm in certain areas. Under those conditions, coastal centers like South Beach in Miami would lie underwater. Entire regions, such as greater Bangkok and the low-lying areas of southern Bangladesh, would sit below annual flood levels, placing millions of people at risk and sparking mass migration across the globe. Wealthier areas like the Netherlands and coastal England will likewise face mounting pressure, with growing swaths of land lying fully inundated for greater periods of time.
But rising seas mean more than higher oceans. The climatic changes that bring sea level rise also result in stronger storms, more intense rainfall, and bigger storm surge. Areas shaped by major rivers, like development along the Mississippi River Valley, will experience increasingly frequent flooding. Without intense intervention or adoption of new approaches to living with water, these regions will see higher levels of deluge, with daily life interrupted on more regular bases for hundreds of thousands of people.
In more arid areas, rising temperatures are slated to bring both more intense rainfall as well as drought. When drought arrives, it will last longer. When rain comes, it will fall harder over shorter periods. The droughts will leave ground more compacted, making it harder for rain to absorb into soils and increasing the likeliness of mudslide. They will also make areas more vulnerable to wildfire. By 2050, the events that have recently wracked Australia with previously unseen levels of devastation will become much more common. From California to the front range of Colorado to Spain and beyond, longer and more dangerous fire seasons will become the norm.
While the precise dates and degrees of change remain a mystery, the general trends are clear – global climate in 2050 will be warmer and its consequences increasingly more extreme.
Johanna Hoffman, a member of our Emerging Fellows program detects the causes of climate change in her second blog post. The views expressed are those of the author and not necessarily those of the APF or its other members.
Climate change comes in two forms. There is the kind caused by natural processes, and there is the kind created by humans. The former has been happening for millennia, produced by a range of factors from the sun’s energy output to shifts in the earth’s orbit. Since the late 18th century, however, that type of climate change has been supplanted. The industrial revolution and its innovations in manufacturing, production, transportation, power use, and more has led to rapid increases of pollutants, carbon dioxide and other emissions that trap heat in the atmosphere, known as greenhouse gases. For millennia, atmospheric carbon dioxide had never been above 325 parts per million. By 1950, levels had blown far past. Since then, massive changes in land use, such as the proliferation of parking lots and other paved surfaces, have made land absorb more sunlight, which our increasingly greenhouse gas filled atmosphere cannot adequately release. As a result, global temperatures continue to rise.
Most of this warming has occurred in the past 35 years, with the five warmest years on record all taking place since 2010. Much of this increased heat and greenhouse gas has been absorbed by our oceans. Since 1969, the top 700 meters of ocean water have warmed more than 0.22 degrees Centigrade and taken in 25% of emitted carbon dioxide. While these numbers may not seem drastic, the impacts are significant. The great ice sheets of the Artic, Antarctic and Greenland are melting at unprecedented rates, with some scientists predicting that the Arctic will be completely free of summer ice within fifteen years. This melting is not restricted to the poles. All across the globe, from the Alps to the Himalayas to the Andes and the Rockies, glaciers are retreating. Satellites show that spring snow cover in the Northern Hemisphere has declined over the last half century, with snow melts starting earlier, putting fresh water access for hundreds of millions at risk.
As glaciers have melted and ocean waters have warmed, seas have continued to rise. Today, seas are roughly 8 inches higher than they were in 1900, making many low-lying countries such as Bangladesh and the Maldives increasingly uninhabitable. A deadly side effect of this rising and warming is ocean acidification. As the ocean absorbs atmospheric CO2, it becomes more acidic in its chemistry. Over the last 150 years, the acidity of surface ocean waters has increased by about 30 percent, creating harsher environments for wide swaths of animal life. Cetaceans, fish species, crustaceans and more are all adversely affected by acidic conditions, threatening the lives and livelihoods of all those who rely on our oceans for sustenance and support.
The climatic changes spurring these shifts mean more than melting glaciers and rising seas. They mean that the current fires devastating the entire continent of Australia will become the norm in regions around the world. They mean that heat waves and severe storms will grow in intensity. They mean that floods will grow more frequent and more powerful, leaving more people inundated for longer periods of time. They mean that more drought will threaten more of our food supplies. They mean that the world that we knew is changing into some more unpredictable and more unwelcome to human habitation that we have ever seen before.