Category Archives: Climate Change

A degree of difference: Living with the consequences of climate change

FILE – This July 4, 2012, file photo provided by Ian Joughin shows surface melt water rushing along the surface of the Greenland Ice Sheet through a supra-glacial stream channel, south-west of Ilulissat, Greenland. Polar ice sheets are now melting three times faster than in the 1990s and the acceleration of the melting, especially in Greenland, has ice scientists worried. Michel Jarraud, the secretary-general for the World Meteorological Organization, says the most troubling climate development in 2012 was the melting at the top of the world. (AP Photo/Ian Joughin)

Global climate change has already had observable effects on the environment. Glaciers have shrunk, ice on rivers and lakes is breaking up earlier, plant and animal ranges have shifted and trees are flowering sooner.

Effects that scientists had predicted in the past would result from global climate change are now occurring: loss of sea ice, accelerated sea level rise and longer, more intense heat waves.

Watch how climate change wreaks havoc on the lives of people living in the Pacific Ocean:

The consequences of Climate Change

High tide regularly floods roads on Kiribati — a common occurrence that may be further exacerbated by sea-level rise caused by the expansion of warmer water and the addition of new water from melting ice. (© Ciril Jazbec)

Sea-level rise

  •  Warmer temperatures cause glaciers to melt faster than they can accumulate new snow. As glaciers and the giant ice sheets on Greenland and Antarctica melt, they add more water into the ocean, which causes sea level to rise.
  • Global sea level has risen by about 8 inches since reliable record keeping began in 1880. It is projected to rise another 1 to 4 feet by 2100.
  • Rising sea level is a threat to people who live near the ocean. Some low-lying areas will have more frequent flooding. Very low-lying land and small islands could be submerged completely.
  • Rising sea level can also harm important coastal ecosystems like mangrove forests and coral reefs.
  • It increases the risk of damage to homes and buildings from storm surges that accompany tropical cyclones. In the next several decades, storm surges and high tides could combine with sea level rise and land subsidence to further increase flooding in many of these regions.
The Storm surge from Hurricane Sandy caused widespread coastal flooding on the New Jersey Coast. US Coast Guard
Hurricane Catarina, a rare South Atlantic tropical cyclone viewed from the International Space Station on March 26, 2004

More frequent extreme weather events

  • e.g. heat waves, flood, drought and tropical cyclones.

    Hurricanes and other tropical storms get their energy from warm ocean water.

    As the top layer of the ocean gets warmer, hurricanes and other tropical storms grow stronger, with faster winds and heavier rain.

    Hurricanes and other storms can cause flooding; damage buildings, roads, and other structures; harm crops; and put people’s lives in danger.

A dzud is an extreme weather phenomenon unique to Mongolia that occurs when large numbers of livestock, mostly cows, sheep and goats, die from starvation or cold.
It usually occurs after a dry summer combines with heavy snowstorms creating an ice crust that makes it difficult for animals to dig through to reach the grass.
Over one million livestock died in 2016’s Dzud. The increasing frequency of such extreme low-temperature events creates mass suffering among the livestock herders of Mongolia.
Severe drought affecting hundreds and thousands in Somalia.
Heavy rainfall events will be more common in a much warmer world.
Drought-Fueled Wildfires Burn 7 Million Acres in U.S. including this one in California, USA
For six million years, the Colorado River has carved some of the wildest geological wonders in North America. Today, its waters nourish over 36 million people. But a steady surge of settlers and drastic climate change are threatening the mighty river.
Some 24,000 hectares of farmland have been affected by severe frost in the Mexican state of Sonora.

Lengthened growing season in the higher latitudes

  • With longer growing seasons, fruit production in Eastern Canada, vine production in Europe has increased. More types of crops such as blackberries and maize can be grown in the UK as the growing season lengthens.
  • However, in China, production of fruits such as apples and cherries or nuts such as almonds and walnuts is reduced as these fruits and nuts require cool weather temperature. Similarly, in Canada, the production of wheat is reduced as temperatures increased.
A man in a tractor prepares a field before sowing winter wheat near the village of Moskovskoye, north of Stavropol in southern Russia,. REUTERS/Eduard Korniyenko. Every degree of rising in local temperature could result in around 40 million tonnes of global yield reduction in wheat, amounting to a loss of a quarter of current global wheat production.
England’s growing season is a month longer than it was a generation ago

Spread of some insect-borne diseases

  • Heavy rainfall allows mosquitoes to breed and grow rapidly. This results in the spread of malaria and dengue fever. Infected people may lose their lives and the government has to spend a lot of money on healthcare for the sick.
  • The researchers found that both unusually high air temperatures and periods of excessive rainfall create environmental conditions that favour bacterial growth. In dry conditions, river levels decrease, and bacteria accumulate in dangerously high concentrations. During excessive rainfall, flooding can spread bacteria to regions that haven’t previously been infected, resulting in fast-spreading epidemics. Even in the past decade, regions of Africa have seen a re-emergence of the disease due to extreme weather, the team reported.
  • For a more detailed article on the spread of diseases, read this: https://theserangoonview.wordpress.com/2017/02/28/cholera-other-illnesses-may-spread-with-climate-change/
A child suffering from malaria lies on a bed at the hospital of Nyarugusu, in the north-west of Tanzania, on June 11, 2015.
Mosquito larvae: Increased rainfall can create stagnant pools of water where mosquitoes breed
Copyright: Flickr/NOAA Photo Library
Officials with the Pan American Health Organization warned about a possible surge in cholera cases because of the widespread flooding caused by Hurricane Matthew. Haiti’s cholera outbreak has killed roughly 10,000 people and sickened more than 800,000 since 2010

Did you know?

Read the full article here:
https://climate.nasa.gov/effects/

The Dzud- Mongolia’s increasingly frequent harsh winters after a summer drought decimates livestock and animals: http://news.bbc.co.uk/2/hi/asia-pacific/8589629.stm http://theubpost.mn/2016/12/23/dzud-may-affect-up-to-150000-herders/

Leave a reply!

  1. After watching the video above, what are three challenges the Kirabati citizens face because of sea-level rise?
  2. What implications does the lengthening growing season have for countries in the higher latitudes?
  3. What is the link between rising global temperatures and the rise in insect-borne diseases? Explain.

Living in a Greenhouse: A thickening blanket around the Earth

A thick blanket of smoke obscures the land as methane fires rage in a US garbage landfill
What is the greenhouse effect?

A layer of greenhouse gases – primarily water vapour, and including much smaller amounts of carbon dioxide, methane and nitrous oxide – acts as a thermal blanket for the Earth, absorbing heat and warming the surface to a life-supporting average of 15 degrees Celsius.

An overview of the Greenhouse Effect. From IPPC Working Group 1 contribution, Science of Climate Change, Second Assessment Report 1996

Essentially this process slows the loss of heat to space, keeping the earth’s surface warmer than it would be without the greenhouse gases. Without this “greenhouse” the Earth’s atmosphere would be an average of about 30-35 oC cooler and life as we know it would not exist.

Then what is the enhanced greenhouse effect?

The enhanced greenhouse effect, sometimes referred to as climate change or global warming, is the impact on the climate from the additional heat retained due to the increased amounts of carbon dioxide and other greenhouse gases (GHGs) that humans have released into the earth’s atmosphere since the industrial revolution.

Black smoke from burning of associated gas, releasing Nitrous Oxide into the atmosphere.

On Earth, human activities are changing the natural greenhouse. Over the last century, the burning of fossil fuels like coal and oil has increased the concentration of atmospheric carbon dioxide (CO2). This happens because the coal or oil burning process combines carbon with oxygen in the air to make CO2. To a lesser extent, the clearing of land for agriculture, industry, and other human activities has increased concentrations of greenhouse gases.

An aerial view of Amazon rainforest burning to clear land for cattle pasture near the city of Novo Progresso, Para state, September 23, 2013. Picture taken on September 23, 2013. REUTERS/Nacho Doce (BRAZIL)
Anthropogenic factors (Human activities) which lead to the enhanced greenhouse effect:
  • Burning of fossil fuels
  • Deforestation 
  • Changing land use (Rice cultivation, cattle ranching, etc)
  • Industrialisation
  • Urbanisation 
Global atmospheric concentrations of four greenhouse gases. From the IPCC 2007 4th Assessment Report
Gases that contribute to the greenhouse effect include:
Water vapour. NASA- Clouds as seen from the ISS

Water vapour

  • The most abundant greenhouse gas, water vapour increases as the Earth’s atmosphere warms, but so does the possibility of clouds and precipitation.
This photo shows a heavily logged concession affiliated with Asia Pulp and Paper, or APP, one of the world’s largest papermakers, on the Indonesian island of Sumatra, in 2010.

Carbon dioxide (CO2)

  •  Carbon dioxide is released through both natural processes such as respiration and volcano eruptions and through human activities such as deforestation, land use changes, and burning fossil fuels.
  •  Carbon oxidation is a process by which carbon in the soil reacts with oxygen in the atmosphere to produce CO². Deforestation exposes soil to sunlight which increases the soil temperature.
  • Humans have thus increased atmospheric CO2 concentration by more than a third since the Industrial Revolution began.
  • To find out about deforestation in the Amazon Rainforest, go here: https://theserangoonview.wordpress.com/2017/02/28/why-is-the-amazon-rainforest-important/
Cattle release methane as a waste gas. A cow releases between 70 and 120 kg of Methane per year on average.

Methane

  • A hydrocarbon gas produced both through natural sources and human activities, including the decomposition of wastes in landfills, agriculture, and especially rice cultivation.
  • Methane is released when dead leaves and manure decompose rapidly in the rice field due to a high level of moisture in the soil.
  • Greenhouse gas emissions associated with livestock supply chains (e.g. Cattle farming) account for 14.5% of all human-caused GHG releases, according to a report published by the UN Food and Agriculture Organisation in 2013.
  • With increased prosperity, people are consuming more meat and dairy products every year, global meat production is projected to more than double from  2001 to 2050.
Burning garbage releases methane and other GHGs as firefighters struggle to keep the fires under control.

Nitrous oxide

  • A powerful greenhouse gas produced by soil cultivation practices, especially the use of commercial and organic fertilisers, fossil fuel combustion, nitric acid production, and biomass burning.
  • The use of chemical fertilisers increases the amount of nitrous oxide in soil. The nitrous oxide is then released when soil is ploughed or when rain flows through the soil.
  • More fossil fuels are burnt to produce energy for household activities in urban areas such as heating, cooking and lighting.
  • More cars, buses and other transportation on the roads also increase greenhouse gas emissions.
  • Constructing infrastructure and producing construction materials also release Nitrous Oxide into the atmosphere.
A farmer sprays a chemical fertiliser containing nitrogen on a wheat field in southern France. Nitrogen fertilisers are a known source of greenhouse gases.

Chlorofluorocarbons (CFCs)

  • Synthetic compounds entirely of industrial origin used in a number of applications, but now largely regulated in production and release to the atmosphere by international agreement for their ability to contribute to the destruction of the ozone layer.
  • To see how the ozone layer protects us, go here: http://earth.rice.edu/mtpe/atmo/atmosphere/topics/ozone/o3.html
  • For a more detailed explanation of protective ozone, go here: https://disc.gsfc.nasa.gov/ozone/additional/science-focus/about-ozone/ozone_atmosphere.shtml
The Hole in the Ozone layer over Antarctica

To understand the consequences of changing the natural composition of atmospheric greenhouse gases, read more here:
https://theserangoonview.wordpress.com/2017/03/09/a-degree-of-difference-living-with-the-consequences-of-climate-change/

Did you know?

What’s it like to have too little or too much of the greenhouse effect? Read below:

Not enough greenhouse effect: The planet Mars has a very thin atmosphere, nearly all carbon dioxide. Because of the low atmospheric pressure, and with little to no methane or water vapour to reinforce the weak greenhouse effect, Mars has a largely frozen surface that shows no evidence of life.

 

Too much greenhouse effect: The atmosphere of Venus, like Mars, is nearly all carbon dioxide. But Venus has about 300 times as much carbon dioxide in its atmosphere as Earth and Mars do, producing a runaway greenhouse effect and a surface temperature hot enough to melt lead.
A man cuts into lumber trees illegally logged in the Amazon forest

Witness the destruction, the crimes, and the exploitation in the Amazon rainforest:  http://blogs.reuters.com/photographers-blog/2013/11/11/from-paradise-to-inferno/

Transportation is one of the largest sources of US global warming emissions – but cleaner vehicles can help

Is there hope for our cities? These guys think so: http://www.ucsusa.org/clean-vehicles/vehicles-air-pollution-and-human-health#.WMVBTlV97IU

Read the full articles here:

http://www.ozcoasts.gov.au/indicators/climate_change.jsp

https://climate.nasa.gov/causes/

Leave a reply!

  1. After watching the video above (from 2:30 – 4:10), what role do Arctic Ice, Clouds, and Water vapour have on controlling the temperature of the earth?
  2. Compare between the ‘Greenhouse Effect’ and the ‘Enhanced Greenhouse Effect’.
  3. Explain how deforestation and changing land use worsen the enhanced greenhouse effect.

 

Climate Change: How do we know?

This graph, based on the comparison of atmospheric samples contained in ice cores and more recent direct measurements, provides evidence that atmospheric CO2 has increased since the Industrial Revolution. (Credit: Vostok ice core data/J.R. Petit et al.; NOAA Mauna Loa CO2 record.)

What is Climate Change?

Climate change is the term used to describe changes in average weather over time periods ranging from decades to millions of years. These changes may be driven by external forces (i.e. predictable orbital variations or solar variation), result from processes internal to the Earth (i.e. plate tectonics or volcanic activity) or be caused by human activities (anthropogenic) such as global warming.

A volcano erupts in Iceland, spewing Greenhouse Gases into the atmosphere.

The current warming trend is of particular significance because most of it is very likely human-induced and proceeding at a rate that is unprecedented in the past 1,300 years.

To see how much the global temperature has risen since 1880, read here: https://www2.ucar.edu/climate/faq/how-much-has-global-temperature-risen-last-100-years

An increase in greenhouse gas levels (global warming) is one of the major impacts that humans have on climate.  These include carbon dioxide, water vapour, nitrous oxide, methane, ozone and halocarbons. There is no question that increased levels of greenhouse gases must cause the Earth to warm in response.

Ice core samples drawn from Greenland, Antarctica, and tropical mountain glaciers show that the Earth’s climate responds to changes in greenhouse gas levels. Ancient evidence can also be found in tree rings, ocean sediments, coral reefs, and layers of sedimentary rocks. This ancient evidence reveals that current warming is occurring roughly ten times faster than the average rate of ice-age-recovery warming.

Every year trees grow a new layer of bark. When you cut through a tree you can see these different layers as rings. The thicker the ring the better the growing conditions were that year. That allows scientists to work out what the temperature, precipitation and carbon dioxide levels are likely to have been for each year.

To understand the greenhouse effect better, go here: https://theserangoonview.wordpress.com/2017/03/09/living-in-a-greenhouse-a-blanket-around-the-earth/

The evidence for rapid climate change is compelling


The Republic of Maldives: Vulnerable to sea level rise
Sea level rise
  • Global sea level rose about 17 centimetres (6.7 inches) in the last century. The rate in the last decade, however, is nearly double that of the last century.


Texas State Park police officer Thomas Bigham walks across the cracked lake bed of O.C. Fisher Lake Wednesday, Aug. 3, 2011, in San Angelo, Texas. A bacteria called Chromatiaceae has turned the 1-to-2 acres of lake water remaining the colour red. A combination of the long periods of 100 plus degree days and the lack of rain in the drought -stricken region has dried up the lake that once spanned over 5400 acres. (AP Photo/Tony Gutierrez)
Global temperature rise
  •  All studies show that Earth has warmed since 1880. Most of the warming occurred in the past 35 years, with 15 of the 16 warmest years on record occurring since 2001. The year 2015 was the first time the global average temperatures were 1 degree Celsius or more above the 1880-1899 average. Even though the 2000s witnessed a solar output decline, surface temperatures continue to increase.

Globally Warming Oceans Are Killing Coral Reefs, like here in Samoa.

Warming oceans
  •  The oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of ocean showing warming of 0.302 degrees celsius since 1969.

This July 4, 2012, file photo provided by Ian Joughin shows surface melt water rushing along the surface of the Greenland Ice Sheet through a supra-glacial stream channel, south-west of Ilulissat, Greenland. Polar ice sheets are now melting three times faster than in the 1990s and the acceleration of the melting, especially in Greenland, has ice scientists worried. Michel Jarraud, secretary-general for the World Meteorological Organization, says the most troubling climate development in 2012 was the melting at the top of the world. (AP Photo/Ian Joughin)
Shrinking ice sheets
  • The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA  shows Greenland lost 150 to 250 cubic kilometres of ice per year between 2002 and 2006, while Antarctica lost about 152 cubic kilometres of ice between 2002 and 2005.

     


Warm temperatures and winds drove record declines in sea ice at both polar regions
Declining Arctic sea ice
  • Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades.


Carroll Glacier, Alaska. August 1906 and June 21, 2004
Glacial retreat
  • Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa.

Global warming is linked to extreme weather events.
Extreme events
  •  The number of record high-temperature events in the United States has been increasing, while the number of record low-temperature events has been decreasing, since 1950. The U.S. has also witnessed increasing numbers of intense rainfall events.

Coral reefs are a major concern in a world of increasing ocean acidification and nutrients.
Ocean acidification
  • Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent. This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans. The amount of carbon dioxide absorbed by the upper layer of the oceans is increasing by about 2 billion tonnes per year.

These two natural-color satellite images of the reduction of snow cover in the Sierra Nevada
Decreased snow cover
  • Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and that the snow is melting earlier.

Did you know?

Understanding global warming and climate change begins young:

 
How do volcanic eruptions affect the climate? Understand global dimming here:

What do volcanic eruptions mean for the climate?
https://www.carbonbrief.org/what-do-volcanic-eruptions-mean-for-the-climate

Calbuco volcano eruption. Credit: Philip Oyarzo Calisto
See how Sunspots and Solar Cycles affect the climate:

Leave a reply!

1. Describe and explain two natural causes of climate change.
2. How has the earth’s climate changed since 1880 and why?
3. Describe how three of the pieces of evidence of climate change will affect you personally.

Why is the Amazon rainforest important?

 The Amazon forest today

Sawmills that process illegally logged trees from the Amazon rainforest are seen near Rio Pardo, in the district of Porto Velho, Rondonia State, Brazil, September 3, 2015. REUTERS/Nacho Doce
A tractor works on a wheat plantation on land that used to be virgin Amazon rainforest near the city of Santarem, Para State, April 20, 2013. REUTERS/Nacho Doce
The Amazon rain forest (R), bordered by deforested land prepared for the planting of soybeans, is pictured in this aerial photo taken over Mato Grosso state in western Brazil, October 4, 2015. REUTERS/Paulo Whitaker
An overview of the houses being built for employees of the Belo Monte hydroelectric dam, planned to be the world’s third largest, in Pimental, near Altamira in Para state, November 23, 2013. REUTERS/Paulo Santos

The Amazon rainforest has long been recognised as a repository of ecological services not only for local tribes and communities but also for the rest of the world. It is also the only rainforest that we have left in terms of size and diversity.

But as forests burn and global warming worsens, the impact of Amazon deforestation continues to gradually undo the fragile ecological processes that have been refined over millions of years.
Ironically, as rainforest continues to disappear, scientific work from the last two decades has shed light on the critical ties that link the health of rainforests to the rest of the world.
Benxi steel mills blowing smoke over residential buildings. Benxi was for long considered one of the most polluted cities in China.
Air pollution hangs heavily over US cities due to the exhaust from fossil-fuel burning vehicles.
The Greenhouse Effect in simple terms.

Filtering and reprocessing the world’s harmful carbon dioxide output

Trees have hidden attributes that play a key role in reducing pollutant levels. Take carbon dioxide (CO2) for example, a gas emitted from both natural and human sources. Over the last 150 years, humans have been pumping massive amounts of CO2 into the air by burning fossil fuels, coal, oil and natural gas – this is a major driver for global climate change.

Deforestation in the Amazon for farmland
Logging causes great deforestation in the Amazon

Carbon dioxide in, oxygen out

Under natural conditions, plants remove CO2 from the atmosphere and absorb it for photosynthesis, an energy-creating process that yields:

  • Oxygen, which is released back into the air
  • Carbon, which allows the plant to grow.

So, without tropical rainforests, the greenhouse effect would likely be even more pronounced, and climate change may possibly get even worse in the future.

To find out more about the Greenhouse Effect, go here:  https://theserangoonview.wordpress.com/2017/03/09/living-in-a-greenhouse-a-blanket-around-the-earth/

Smoke billows during a fire in an area of the Amazon rainforest at the Kuikuro territory in the Xingu National Park, Mato Grosso, Brazil, October 4, 2015. REUTERS/Paulo Whitaker

Amazon rainforests and carbon dioxide

What forests take from the air, they can also give back. When forests burn, tree carbon matter is released in the form of CO2, which pollutes the atmosphere, and of which there are already excessive quantities.
Where rainforest and savanna once stood, pastures for cattle ranching are now appearing. Pastures teem with termites and cattle, whose metabolic activities also release CO2, although their contribution to atmospheric pollution is under much debate.
With the forests gone, CO2 is no longer transformed through photosynthesis, and the crops that replace forests only absorb a fraction of CO2 compared to rainforests. Along with industrial pollution, rampant deforestation in South America and elsewhere has significantly increased the amount of CO2 in the atmosphere.
Amazon, Brazil, near the Venezuelan frontier. Tropical rainforest, deforestation. Land which has been systematically deforested and logged then given over to cattle ranching.

The importance of the Amazon rainforest for local and global climate

Tropical forests and woodlands (e.g. savannas) exchange vast amounts of water and energy with the atmosphere and are thought to be important in controlling local and regional climates.

Water released by plants into the atmosphere through evapotranspiration (evaporation and plant transpiration) and to the ocean by the rivers, influences world climate and the circulation of ocean currents. This works as a feedback mechanism, as the process also sustains the regional climate on which it depends.

Transpiration from the Amazon is vital for the water cycle to take place

Find out about the impacts of climate change on the Amazon  

The Amazon rainforest could cure you

What is the connection between the blue-green pills in your bathroom cupboard and the Amazon wildlife? The natural roots of medicine. For millennia, humans have used insects, plants and other organisms in the region for a variety of uses; and that includes agriculture, clothing and, of course, cures for diseases.

The Wasai tree’s Red Roots. Great for kidney health, the root of the Wasai tree is often ground up and prescribed as a diuretic.

Indigenous people such as the Yanomamo and other groups of mixed ancestry (e.g. the mestizos of Peru or the Caboclos of Brazil) have perfected the use of chemical compounds found in plants and animals. Knowledge of using these plants is usually held by a medicine man (shaman), who passes on this tradition to an apprentice, a process which has been ongoing for centuries and that forms an integral part of people’s identity.

With rainforests going fast, the continuity of this knowledge for the benefit of future generations is under threat.

Yanomamo girl, 1997, Brazil

Untapped potential of the Amazon’s plants

Scientists believe that less than half of 1% of flowering plant species have been studied in detail for their medicinal potential. As the Amazon rainforest biome slowly shrinks in size, so does the richness of wildlife found in its forests, along with the potential use of plants and animals that remain undiscovered.

Brazil nuts: new superfood?

Read the full article here: 

http://wwf.panda.org/what_we_do/where_we_work/amazon/about_the_amazon/why_amazon_important/

Find out more!

Cholera, Other Illnesses May Spread with Climate Change

L’ARCAHAIE, HAITI – OCTOBER 28: A man suffering from cholera rests in bed at a rural hospital October 28, 2010, in L’Arcahaie, Haiti. Haiti, one of the poorest nations in the Western Hemisphere, has been further unsettled by an outbreak of cholera which has killed at least 300 people so far. The epidemic has affected the central Artibonite and Central Plateau regions with 3,612 cases so far on record. While authorities believe the outbreak is contained, they believe it has not yet peaked. There is also fear that the deadly diarrheal disease could migrate to the sprawling camps for the hundreds of thousands of Haitians displaced by the earthquake. (Photo by Spencer Platt/Getty Images)

Infectious-disease specialists are concerned that climate change is contributing to the spread of certain diseases, including the germs that cause cholera and other diarrheal illnesses.

Data now suggest that the locations where certain pathogens are found have changed, said Dr Glenn Morris, the director of the Emerging Pathogens Institute at the University of Florida. Morris gave a talk here today (Feb. 16) at the Climate & Health Meeting, a gathering of experts from public health organisations, universities and advocacy groups that addressed the health impacts of climate change.

Officials with the Pan American Health Organization warned about a possible surge in cholera cases because of the widespread flooding caused by Matthew. Haiti’s cholera outbreak has killed roughly 10,000 people and sickened more than 800,000 since 2010

Pathogens tend to live in places that have ideal sets of conditions, Morris said. For example, these bugs may have evolved to function best within certain temperature ranges, he said. And as climate change occurs and global average temperatures rise, researchers are beginning to see some indications that the areas where certain pathogens can live are shifting, he said.

“We are seeing the spread of pathogens to new ecological niches,” Morris said.

And the pathogens that live in water are among scientists’ top concerns, Morris told Live Science.

Temperature anomalies (in degrees Celsius) of various regions around the world in August 2014.
Credit: NASA

Vibrio and algal blooms

One group of bacteria, called Vibrio species, are particularly well-studied, Morris said. Vibro bacteria are responsible for cholera and other diarrheal diseases. Although cholera can be treated by rehydration according to the World Health Organization, the disease can still be fatal if not treated quickly enough.

Vibrio bacteria live in seawater, and with sea temperatures rising, scientists have recently observed a northward shift in the bacteria’s range, he said. In addition, diseases such as cholera often spread following events like flooding, which may become more common with climate change, Morris said.

Boats going through an algal bloom on Lake Erie near Toledo, Ohio.

Other waterborne diseases can come from harmful algal blooms, which are caused by toxic forms of algae, Morris said. Algal blooms have been linked to illnesses such as ciguatera, which people get from eating fish that contain toxins produced by the algae Gambierdiscus Toxicus, according to the Centers for Disease Control and Prevention. Another illness linked to harmful algal blooms is amnesic shellfish poisoning, which is caused by eating contaminated shellfish.

Warming seas are breeding cholera-causing bacteria in the north Atlantic, poisoning shellfish and other seafood.

These harmful algal blooms are showing up in places where they previously didn’t occur, including the Pacific Northwest, Alaska and Maine, Morris said.

This dead fish suffocated during the massive algae bloom in Lake Erie in 2011.
Toxic algal bloom in California’s Klamath River
An Aedes aegypti mosquito, the chief vector of Zika virus.

But what about mosquitos?

Morris noted that there have also been some concerns about mosquito-borne diseases, because of evidence suggesting that certain species of the insect are moving farther north than they used to. But it’s unclear what impact this will have in the long term, Morris told Live Science. He noted that in developed countries, including U.S., many aspects of homes help protect people against mosquito bites, such as the use of window screens and air conditioning.

While the illnesses Morris noted in his talk are all known diseases, they can still pose public health challenges when they move into parts of the world where they haven’t occurred before, he said.

Mosquito larvae: Increased rainfall can create stagnant pools of water where mosquitoes breed
Copyright: Flickr/NOAA Photo Library

“We’ve always thought about tropical areas as having particularly significant problems with infectious diseases,” but “we’re starting to see some greater indications that those diseases may be creeping up here” in the U.S., he said.

Morris said that the U.S. can handle those diseases, but the bigger concern is that pathogens are always evolving. Microorganisms may be able to change over time, “and increasingly take advantage of conditions that may not have been present before,” he said.

Read the full article here: http://www.livescience.com/57925-infectious-diseases-may-spread-with-climate-change.html

Did you know?

Read how extreme weather contributes to the spread of diseases:

http://www.independent.com.mt/articles/2016-10-06/world-news/108-deaths-reported-during-hurricane-Matthew-which-hard-hit-Haiti-6736164817

https://www.csis.org/blogs/smart-global-health/epidemic-after-earthquake-cholera-outbreak-haiti-part-1

http://www.techtimes.com/articles/198128/20170218/how-cholera-and-diarrhea-pathogens-spread-northward-because-of-climate-change.htm

https://news.vice.com/article/warming-seas-are-breeding-cholera-causing-bacteria-in-the-north-atlantic

A fisherman cups algae-choked water from China’s Chaohu Lake in 2009.
Two people row their way across algae-infested Chaohu Lake, China, in a 2009 picture.
Fingers of sediment and green swirls of algae are visible in Lake Erie on March 21, 2012.

Learn more about Algal blooms:

http://news.nationalgeographic.com/news/2014/08/140804-harmful-algal-bloom-lake-erie-climate-change-science/ 

https://en.wikipedia.org/wiki/Algal_bloom

Leave a reply!

  1. What does the rise in sea temperatures (an effect of climate change) directly affect the health of humans?
  2. Why are temperate countries like the USA starting to be more concerned about mosquito-borne diseases?
  3. Why is eating shellfish becoming riskier with rising sea temperatures?

Investigating the world through the Humanities

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