Climate change impact

Because the global climate is a connected system climate change impacts are felt everywhere.

Among the most important climate change impacts are:

Climage change impacts rising sea levels. Average sea level around the world rose about 8 inches (20 cm) in the past 100 years; climate scientists expect it to rise more and more rapidly in the next 100 years as part of climate change impacts.

Coastal cities such as New York are already seeing an increased number of flooding events and by 2050 many such cities may require seawalls to survive. Estimates vary, but conservatively sea levels are expected to rise 1 to 4 feet (30 to 100 cm), enough to flood many small Pacific island states (Vanatu), famous beach resorts (Hilton Head) and coastal cities (Bangkok, Boston).

If the Greenland ice cap and/or the Antarctic ice shelf collapses, sea levels could rise by as much as 20 ft (6 m), inundating, for example, large parts of Florida, the Gulf Coast, New Orleans and Houston.

climate change impacts Rising sea levels

(Source: National Climate Assessment )

Projections suggest climate change impacts within the next 100 years, if not sooner, the world’s glaciers will have disappeared, as will the Polar ice cap, and the huge Antarctic ice shelf, Greenland may be green again, and snow will have become a rare phenomenon at what are now the world’s most popular ski resorts.

climate change impact on arctic-sea-ice-loss

(Source: National Climate Assessment )

To view an interactive map of changing polar ice coverage, 1979 to 2015 click here.

While the specific conditions that produce rainfall will not change, climate change impacts the amount of water in the atmosphere and will increase producing violent downpours instead of steady showers when it does rain.

Hurricanes and typhoons will increase in power, and flooding will become more common.

Anyone in the United States who has tried to buy storm and flood insurance in the past few years knows that the insurance industry is completely convinced that climate change is raising sea levels and increasing the number of major storms and floods. (To understand the insurance industry’s thinking on the subject, consider the chart below compiled by Munich Re-Insurance.)

climate change impacts

(Source: Environmental Change @ Western)
climate change impacts Flooding
(Source: Munich RE)

Despite downpours in some places, droughts and prolonged heatwaves will become common.

Rising temperatures are hardly surprising, although they do not mean that some parts of the world will not “enjoy” record cold temperatures and terrible winter storms. (Heating disturbs the entire global weather system and can shift cold upper air currents as well as hot dry ones. Single snowballs and snowstorms do not make climate change refutations.)

Increasingly, however, hot, dry places will get hotter and drier, and places that were once temperate and had regular rainfall will become much hotter and much drier.

The string of record high temperature years and the record number of global droughts of the past decade will become the norm, not the surprise that they have seemed.

climate change impacts drought

(Source: EPA adopted from Dai, Drought Under Global Warming)

As the world warms, entire ecosystems will move.

Already rising temperatures at the equator have pushed such staple crops as rice north into once cooler areas, many fish species have migrated long distances to stay in waters that are the proper temperature for them.

In once colder waters, this may increase fishermen’s catches; in warmer waters, it may eliminate fishing; in many places, such as on the East Coast of the US, it will require fishermen to go further to reach fishing grounds.

Changing fisheries
climate change impacts fisheries
(Source: NOAA Fisheries)

Farmers in temperate zones are finding drier conditions difficult for crops such as corn and wheat, and once prime growing zones are now threatened.

Some areas may see complete ecological change.

In California and on the East Coast, for example, climate change impacts and warming will soon fundamentally change the forests; in Europe, hundreds of plants species will disappear and hundreds more will move thousands of miles.

Shift in forest types
climate change impacts on forests and ecosystems
(Source: Slide Share)
California tree species changes
climate change impacts California tree species
(Source: National Climate Assessment )
Europe species changes
climate change impacts on Europe species
(Source: European Environment Agency)

One of the most striking impacts of rising temperatures is felt in global agriculture, although these impacts are felt very differently in the largely temperate developed world and in the more tropical developing world.

Different crops grow best at quite specific temperatures and when those temperatures change, their productivity changes significantly.

In North America, for example, rising temperatures may reduce corn and wheat productivity in the US mid-west, but expand production and productivity north of the border in Canada.

The productivity of rice, the staple food of more than one third of the world’s population, declines 10% with every 1⁰ C increase in temperature.

Past climate induced problems have been offset by major advances in rice technology and ever larger applications of fertilizer; expectations are that in Thailand, the world’s largest exporter of rice, however, future increases in temperatures may reduce production 25% by 2050.

At the same time, global population models suggest that developing world will add 3 billion people by 2050 and that developing world food producers must double staple food crop production by then simply to maintain current levels of food consumption.

Climate change and food security
climate change impacts food security
(Source: Slideshare)
Climate change impacts on production
climate change impacts production
(Source: Climate Impacts)
Temperatures and food production
climate change impacts temperature and lost food production
(Source: Slideshare)

Rising temperatures favor agricultural pests, diseases and disease vectors.

Pest populations are on the rise and illnesses once found only in limited, tropical areas are now becoming endemic in much wider zones.

In Southeast Asia, for example, where malaria had been reduced to a wet season only disease in most areas, it is again endemic almost everywhere year around.

Likewise, dengue fever, once largely confined to tropical areas, has become endemic to the entire region.

Increased temperatures also increase the reproduction rates of microbes and insects, speeding up the rate at which they develop resistance to control measures and drugs (a problem already observed with malaria in Southeast Asia).

Pest Generations present to 2050
climate change impacts pest generations
(Source: CCAFS )

climate change impacts health

(Source: CDC)
West Nile virus risk
climate change impacts west nile virus risk
(Source: Climate Confidential)
Dengue distribution by 2050
climate change impacts spread of dengue fever
(Source: Nature.com )

climate change impacts zika virus spread

(Source: Environmental Defense Fund)
Projected change in risk of Malaria
climate change impacts malaria
(Source: Global Warming – So what?)

Rising temperature and rising CO2 levels are making the world’s oceans more acidic (lowering their pH). More acidic seawater damages the ability of sea creatures to make shells. Shelled species, tiny and large, are the base of the ocean food pyramid and their loss threatens the food producing potential of the oceans.

climate change impacts ocean acidity-ph-scale
(Source: Environmental Protection Agency )

climate change impacts sea life

(Source: National Climate Assessment)

Next: What have we done to manage climate change?