advancing preventive and reactive response measures. without acknowledging the climate changes that make environments more habitable for disease carriers, policy and infrastructure will lag behind vector borne disease spread. the human cost associated with denying climate change science is one that concerns many governments. in the united states, the centers for disease control and prevention (cdc) is conducting a grant program called building resilience against climate effects (brace) which details a 5 step process for combating climate effects like tick borne disease spread. as is the case when responding to other vectors and effects of climate change, vulnerable populations including children and the elderly will need to be prioritized by any intervention. productive policies in the u.s. and the world need to accurately model changes in vector populations as well as the burden of disease, educate the public on ways to mitigate infection, and prepare health systems for the increasing disease load. leishmaniasis leishmaniasis is a neglected tropical disease, caused by parasites of the genus leishmania and transmitted by sandflies; it is distributed mostly in tropical and subtropical regions around the world, wherever the sand fly vector and reservoir hosts are present. the disease can manifest in several ways depending on the infecting species of parasite: in cutaneous leishmaniasis, ulcers develop on the skin leaving stigmatizing scars, while in visceral leishmaniasis parasites invade internal organs and can be fatal if untreated. the who estimates 12 million people around the world are living with leishmaniasis, and the risk factors for this disease include poverty, urbanization, deforestation, and climate change. as in other vector-borne diseases, one of the reasons climate changes can affect the incidence of leishmaniasis is the susceptibility of the sandfly vectors to changes in temperature, rainfall and humidity; these conditions will alter their range of distribution and seasonality. for example, modelling studies have predicted that climate change will increase suitable conditions for phlebotomus vector species in central europe. another model that looked at the distribution of lutzomyia longipalpis, an important visceral leishmaniasis vector, suggested an increased range of this species in the amazon basin. a different study model that factored data on climate, policy and socio-economic changes of land use, found that the effects were different for cutaneous and visceral leishmaniasis, emphasizing the importance of considering each disease and region separately. parasite development inside the sandfly can also be affected by temperature changes. for instance, leishmania peruviana infections were lost during sandfly defecation when the infected vector was kept at higher temperatures, whereas in the same experiment leishmania infantum and leishmania braziliensis temperature seemed to make no difference. ebola ebola is one of the deadliest viruses, starting out as a small outbreak and eventually turning into a major global issue. the first time the virus was noticed was in 1976 near the ebola river in democratic republic of congo. the virus has been infecting people from time to time, leading to outbreaks in several african countries. the average case fatality rate of the ebola virus is approximately 40% and there have been more than 28,600 cases with 11,310 deaths. recent studies are holding climate change liable for the uptick in ebola. many researchers are linking deforestation to the disease, observing that change in the landscape increases wildlife contact with humans. ebola virus is typically found in animals of the wild and can be transmitted from these animals to humans when exposed to infected bodily fluids. the virus can also be transmitted from another human when in direct contact with the virus hosts blood, vomit, or feces. seasonal droughts alongside strong winds, thunderstorms, heat waves, floods, landslides, and a change in rainfall patterns also impact wildlife migration. these conditions pull them away from their natural environment and closer to human proximity. one example of an ebola outbreak caused by climate change or a shift in nature was seen during the drought of central africa. this ultimately amplified food insecurity leading west african communities to eat animals such as bats who were infected with the virus. zika virus zika virus, a vector-borne virus was first observed in 1947 and historically presented in cluster outbreaks in the tropical regions of africa and asia. zika virus epidemics have affected larger populations including micronesia and south pacific islands in 2007, and the americas in 2013. brazil has experienced one of the largest outbreaks of zika virus with approximately 1.5 million cases reported in 2015. pregnant women infected with zika virus are at a higher risk of giving birth to children with congenital malformations, including microcephaly. in the context of climate change and temperature rise, it is predicted that zika virus will affect more than 1.3 billion people by 2050. this is largely due to the expansion of environments conducive to vector growth and life cycles, such as those with temperatures ranging from 23.9 °c to 34 °c. mosquito behaviors are also affected by the change in temperature including increased breeding and biting rates. furthermore, extreme climate patterns, including drought, floods and heatwaves are known to exacerbate the proliferation of mosquito breeding ground and as a result, escalate the rate of virus-borne diseases. in addition to zika virus transmission, mosquito-borne diseases such as yellow fever and dengue fever are also predicted to be more prevalent due to climate change. covid-19 the united nations environment programme classifies the covid-19 as zoonotic, meaning the virus jumped from animals to humans. the emergence of zoonotic diseases has been increasing, in part due to climate change and anthropogenic habitat destruction. factors contributing to the increased emergence include fluctuations in temperature and humidity, livestock farming, wildlife trade, habitat loss, and environmental degradation. the united nations environment programme states that: "the most fundamental way to protect ourselves from zoonotic diseases is to prevent destruction of nature. where ecosystems are healthy and bio-diverse, they are resilient, adaptable and help to regulate diseases." the head of the world health organization, tedros adhanom ghebreyesus, in a special video message spoke about the link between the health of the biosphere and prevention of pandemics like the covid-19 pandemic and highlighted that efforts for improving health will not work without stopping climate change. the world health organization created a special page dedicated to frequently asked questions about coronavirus and climate change, including the link between climate change and the emergence of new zoonotic diseases. as of 24 november 2020 it summarized the current knowledge about the issue as follows:there is no evidence of a direct connection between climate change and the emergence or transmission of covid-19 disease. as the disease is now well established in the human population, efforts should focus on reducing transmission and treating patients. however, climate change may indirectly affect the covid-19 response, as it undermines environmental determinants of health, and places additional stress on health systems. most emerging infectious diseases and almost all recent pandemics, originate in wildlife, and evidence that increasing human pressure on the natural environment may drive disease emergence. strengthening health systems, improved surveillance of infectious disease in wildlife, livestock and humans, and greater protection of biodiversity and the natural environment, should reduce the risks of future outbreaks of other new diseases." the page specifically notes that climate change, possibly helps to the spreading of the pandemic, because it lead to water scarcity and water is crucial to different measures needed for stopping the pandemic. other studies a 2021 study found possible links between climate change and transmission of covid-19 by bats. the authors found that climate-driven changes in the distribution and richness of bat species increased the likelihood of bat-borne coronaviruses in the yunnan province, myanmar, and laos. this region was also the habitat of sunda pangolins and masked palm civits which were suspected as intermediate hosts of covid-19 between bats and humans. the authors suggest, therefore, that climate change possibly contributed to some extent to the emergence of the pandemic. climate changed in bat habitats may have also driven them closer to populated areas. increased aridity and drought periods are predicted to push bats out of their endemic areas and into populated areas. this creates a knock-on effect of increasing their interactions with humans and hence the likelihood of zoonotic disease transfer. climate conditions during the covid-19 pandemic also affected the transferability of the virus. this was partly due to human reactions to extreme weather for example people being more like to socially isolate during heavy rain and therefore less likely to contractive coronavirus from others. warmer weather may have also created less suitable conditions for covid-19 to survive and spread virally. others emergence of new infectious diseases a concern about the emergence of new diseases from the fungal kingdom. mammals have endothermy and homeothermy, which allows them to maintain elevated body temperature through life; but it can be defeated if the fungi were to adapt to higher temperatures and survive in the body. fungi that are pathogenic for insects can be experimentally adapted to replicate at mammalian temperatures through cycles of progressive warming. this demonstrates that fungi are able to adapt rapidly to higher temperatures. the emergence of candida auris on three continents is proposed to be as a result of global warming and has raised the danger that increased warmth by itself will trigger adaptations on certain microbes to make them pathogenic for humans. climate change may lead to dramatic increases in prevalence of a variety of infectious diseases. beginning in the mid-'70s, an "emergence, resurgence and redistribution of infectious diseases" has occurred. reasons for this are likely multi-causal, dependent on a variety of social, environmental and climatic factors, however, many argue that the "volatility of infectious disease may be one of the earliest biological expressions of climate instability". though many infectious diseases are affected by changes in climate, vector-borne diseases, such as malaria, dengue fever and leishmaniasis, present the strongest causal relationship. one major reason that change in climate increases the prevalence of vector borne disease is that temperature and rainfall play a key role in the distribution, magnitude, and viral capacity of mosquitoes, who are primary vectors for many vectors borne diseases. observation and research detect a shift of pests and pathogens in the distribution away from the equator and towards earth's poles. a tool that has been used to predict this distribution trend is the dynamic mosquito simulation process (dymsim). dymsim uses epidemiological and entomological data and practices to model future mosquito distributions based upon climate conditions and mosquitos living in the area. this modeling technique helps identify the distribution of specific species of mosquito, some of which are more susceptible to viral infection than others. viral spillovers in 2022, a big study dedicated to the link between climate change and zoonosis was published. the study found a strong link between climate change and the epidemics emergence in the last 15 years as it causes a massive migration of species to new areas, consequently, contacts between different species who had not met each other before. even in the scenario with weak climatic changes, there will be 15,000 spillovers of viruses to new hosts in the next decades. the areas with the most possibilities to spillover are the mountainous tropical regions of africa and southeast asia. southeast asia is more vulnerable as it has a large number of bat species that generally do not mix but can do it easily by flying if climate change forces them to migrate. it is projected that interspecies viral sharing, that can lead to novel viral spillovers, will increase due to ongoing climate change-caused geographic range-shifts of mammals (most importantly bats). risk hotspots would mainly be located at "high elevations, in biodiversity hotspots, and in areas of high human population density in asia and africa". mosquito transmitted diseases environmental changes such as deforestation could increase local temperatures in the highlands thus could enhance the vectorial capacity of the anopheles. anopheles mosquitoes are responsible for the transmission of a number of diseases in the world, such as, malaria, lymphatic filariasis and viruses that can cause such ailments, like the o'nyong'nyong virus. environmental changes, climate variability, and climate change are such factors that could affect biology and disease ecology of anopheles vectors and their disease transmission potential. climate change is expected to lead to latitudinal and altitudinal temperature increases. global warming projections indicate that surface air warming for a "high scenario" is 4 c, with a likely