Toxic Algae Blooms in a Changing Climate

Harmful algal blooms (HABs) caused by cyanobacteria are increasing globally due to warming temperatures, heavier rainfall, and nutrient pollution. These blooms produce toxins that cause acute illnesses in humans, long-term organ damage, and death in wildlife. Mitigation requires reducing carbon emissions and nutrient runoff from agricultural and urban sources.

• Freshwater harmful algal blooms (HABs) are driven by cyanobacteria, which thrive in warm water and feed on nitrogen and phosphorus runoff from agricultural operations, residential fertilizers, and wastewater discharge.
• Climate change amplifies HAB risks globally by increasing water temperatures and causing heavier rainfall, which flushes more nutrients into freshwater bodies.
• Exposure to cyanotoxins through direct contact, inhalation, or ingestion of contaminated water and food can cause acute symptoms like respiratory distress and gastrointestinal upset, as well as long-term liver damage and potential links to neurodegenerative diseases such as ALS, Parkinson’s, and Alzheimer’s.
• HABs pose lethal risks to animals, including fish, birds, and dogs, the latter of which can be exposed by drinking, swimming, or grooming themselves after water contact.
• Risk mitigation involves long-term global reductions in carbon emissions to slow warming and local efforts to reduce nutrient pollution, while short-term risks can be managed using chemical algaecides.

APA

Paerl, H., Laughinghouse, D., Chatterjee, S., & Scott, G. (2022). Toxic Algae Blooms in a Changing Climate. Climate Central. https://www.climatecentral.org/climate-matters/harmful-algal-blooms

Chicago

Paerl, Hans, Dail Laughinghouse, Saurabh Chatterjee, and Geoff Scott. Toxic Algae Blooms in a Changing Climate. Climate Central, 2022. https://www.climatecentral.org/climate-matters/harmful-algal-blooms.

Wikipedia

{{cite report |last1=Paerl |first1=Hans |last2=Laughinghouse |first2=Dail |last3=Chatterjee |first3=Saurabh |last4=Scott |first4=Geoff |title=Toxic Algae Blooms in a Changing Climate |publisher=Climate Central |date=10 August 2022 |url=https://www.climatecentral.org/climate-matters/harmful-algal-blooms |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{paerl2022toxic, author = {Paerl, Hans and Laughinghouse, Dail and Chatterjee, Saurabh and Scott, Geoff}, title = {{Toxic Algae Blooms in a Changing Climate}}, institution = {Climate Central}, year = {2022}, month = aug, url = {https://www.climatecentral.org/climate-matters/harmful-algal-blooms}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }