The challenges seen from a veterinarian's point of view

Concequences of the changes

Below you can read about the concequences of climate change and loss of nature, seen from a veterinarian’s perspective. You will also find further information on zoonoses, antibiotic resistance and environmental destruction under one health (in Norwegian). You can read more on animal health personnel’s obligations and  commitment here (in Norwegian)

More animal diseases

Globally, the World Organization for Animal Health (WOAH, formerly OIE) expresses great concern about the increase in animal diseases as a result of climate change. Examples are diseases that are spread by ticks, mosquitoes and blackflies (vector-borne), parasitic diseases, pasteurellosis, bird flu, anthrax, anthrax emphysema, rabies, and tuberculosis. In lakes and seas, new diseases will be able to spread when the water temperature rises. Increased diseaseburden in animals threatens the world’s food security, gives an increased climate footprint, and is an animal welfare problem that can’t be ignored.

We also see national consequences: A milder climate leads to wood ticks penetrating further away from the coasts and further north. Wood ticks can transmit infectious agents that cause Lyme disease, anaplasmosis and tick-borne encephalitis (TBE). Milder winters contribute to a greater problem with parasites among livestock on spring pastures. New parasites can gain ground, such as heartworm in dogs. Vector-borne diseases are spreading from the continent. Examples are bluetongue, Q-fever and Schmallenberg virus in ruminants and West Nile virus in birds, horses and humans. Mild winters provide better living conditions for foreign species such as wild boars that can carry African swine fever, salmonella and mycoplasma. With increased temperatures in lakes and the ocean follows more diseases, including the parasitic disease proliferative kidney disease (PKD) and salmon lice in Atlantic salmon. Sick animals experience reduced animal welfare. Limiting temperature rise is vital to preserve good animal and human health.


Increased amounts of human diseases that originate from animals (zoonoses)


Infectious diseases (viruses, bacteria and parasites) that spread between animals and humans are called zoonoses. Many zoonoses are easily transmitted between humans and animals. Within these there are many so-called neglected zoonoses that are very important in terms of human health in developing countries. We have created a world with close communication between people via travel and trade, and with large-scale trade in food, livestock and wild animals. All the warnings that scientists have given in recent years have had little effect. The Covid-19 pandemic was consequently a wake-up call for the entire world in 2020. It is a disease of zoonotic origin, like many of the most dangerous infectious diseases for humans. 

Climate change is increasing the frequency and changing the spread of zoonoses worldwide – including Norway. This happens because many infectious agents survive longer or multiply more efficiently in warmer and more humid environments, and because several insect species that transmit infectious agents can establish themselves and contribute to the spread of these diseases among people and animals. We see a greater spread of ticks and insects that may carry zoonotic bacteria or viruses. 

Humans are changing important habitats for wild animals, for instance by cutting down tropical forests and expanding cities. Human activity is taking over areas that were previously reserved for animals. In addition, we see that wild animals also become urban by establishing themselves in cities. The total effect of climate change, climate-based vegetation change and human intervention in nature, is that we all become more vulnerable. We must therefore prepare to deal with more zoonotic diseases in the future. Increased travel and trade contribute to making the situation unstable. Better national and international systems will be required to handle these challenges.

Veterinarians, doctors and other professionals have worked together on measures at various levels in order to limit the spread of infectious diseases between animals, people and the environment. This «one health» approach has become more important recently and should be reinforced.

Lack of clean water

All around the world we see glaciers melting and lakes drying up because of climate change. Water shortages will become an increasing problem, both in terms of quantity and quality. Stronger and more frequent extreme weather destroys drinking water. Impure water can transmit potentially life-threatening diseases, such as viral diarrhoea, cholera, hepatitis and a number of parasites. Wars and migrations will escalate as a result of water shortages. Securing drinking water reservoirs for the world’s people and animals is a shared responsibility. 

In Norway we will also face challenges with inferior water quality because of more extreme weather, higher temperatures and poor nature management. In the Oslo Fjord, we have acquired the heat-loving bacterium Vibrio vulnificus, which causes wound infections and, in the worst case, sepsis in swimmers. We are also seeing more algae blooms with toxin formation. Floods and droughts destroy drinking water supplies and create health risks. Some agriculture and forestry, as well as digging ditches and draining wetlands, have an adverse effect on water quality and water storage. Increased rainwater in stormwater systems will overload the drainage systems risking sewage pollution in lakes and rivers. Large investments will be required, updating and increasing the capacity of water treatment plants, stormwater systems and drainage systems in order to confront climate change.

Impaired animal welfare and livelihoods for wild animals in water and on land

Climate change contributes to changes in nature – in the sea and on land. The Animal Welfare Act states that «Animals have intrinsic value regardless of the utility value they may have for humans. Animals must be treated well and protected against the risk of unnecessary stress and strain». The law also applies to all wild animals – in water and on land. It is the course of nature that wild animals must adapt to variations in weather and climate, in competition with conspecifics and other species. But the changes we are now witnessing, are happening so rapidly that many species do not have time to adapt. This also applies to animals in lakes and the ocean. Warmer, less oxygenated, and more acidic water negatively affects them and their food supply. Animal populations will move, to the extent that they are able to, and species diversity may become poorer. Such changes to living conditions will result in deteriorating animal welfare and animal health. 

The temperature changes will be greatest in the polar regions. In the Arctic, where polar bears depend on being able to catch seals on the ice, melting of the ice caps leads to food shortages. In Svalbard and mainland Norway, shorter winters with more unpredictable weather and unstable temperatures will lead to frozen and closed pastures for a number of animals, such as small rodents and reindeer. The fact that spring sets in earlier already means that insect-eating migratory and non-migratory birds lose offspring, either because of a lack of insects as a result of sudden temperature drops or because the insect peak comes before the migratory birds arrive. A premature spring also means insufficient access to nutritious sprouts for the herbivores’ offspring. Warmer summers become challenging for reindeer, who can no longer rely on glaciers for shelter against troublesome reindeer warble fly. 

Several seabirds, including puffins and black-legged kittiwake, are struggling with a poorer supply of food, respectively a lack of herring fry and sea butterflies in New Foundland where the black-legged kittiwake spend their winters. The sea butterflies, species of snails, are very vulnerable to acidification of the ocean. For marine life, climate change will have the greatest negative influence on life and diversity of species in oceans further from Norway, but we will also see the changes here. Several infectious diseases are mentioned under the section on animal diseases (above). The ice shelf is important with its abundant food reserves, it is moving north. Important fish stocks must follow it and may disappear from Arctic areas and the Norwegian coast. The cod is heading north in the Barents Sea and the mackerel is now also found in northern Norway and at Svalbard. Our deep-water and cold-water corals, with their rich natural diversity, could be threatened by ocean acidification.

Loss of nature and diversity

Climate change and our predation on nature in the sea and on land leads to a reduction in populations, weakening of species as a result of loss of genetic variation, loss of natural diversity and therefore small and large ecosystems collapses. The International Nature Panel (IPBES) reports that many populations have been reduced by 50 % in the last 50 years. More and more species are at risk of extinction. For mankind, this entails lost resources, for example in terms of food and the development of new medicines. The situation is very serious. We are facing a dramatic increase in multi-resistant bacteria against antibiotics, which one believes will be a far greater challenge than the ongoing Covid-19 pandemic. According to the same report, 75% of land areas have been significantly changed, 66 % of the oceans are increasingly affected and 85 % of the world’s wetlands have been lost. Therefore, it is highly problematic that raw materials for feed, fodder, food and other things are imported from areas in countries that are destroying the remaining nature at a rapid pace, such as the important rainforests in the Amazon, Central Africa, South-East Asia and Oceania.

Overfishing leads to a reduction in fish stocks and destruction of habitats where fish larvae develop. Ballast water from ships and a rise in sea temperature means that species and plants that would not naturally have growing conditions in our coastal and marine areas can thrive and disturb original species. Fishermen report species they’ve never seen before. Warmer, less oxygenated, and more acidic water will create an imbalance in ecosystems and diminish natural diversity. Arctic cod is an example of a species in decline. This is a key species in the Barents Sea. It is unknown what consequences its decline may have for the entire ecosystem.

Even in Norway, we have little unspoilt nature remaining. What we have left is increasingly fragmented. Power generation, infrastructure, cabin construction, alien species, intensive agriculture and forestry are examples of threatening factors that destroy habitats for animals in virgin forests, marshes, wetlands, and coastal landscapes. Changes in habitats are the main reason why species end up on the red list of threatended species, and protection of habitats is critical to safeguarding diversity of species. Road construction and flood protection measures destroy habitats in rivers and streams and prevent natural reproduction of both anadromous and freshwater fish.

Loss of natural diversity is as big a threat as climate change. Loss of nature is also linked to climate change, and these can reinforce each other. For example, if the remaining rainforests are destroyed, it changes the climate and vice versa.