Their study stems from an urgent virtual workshop convened by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) to investigate the links between pandemic risk and the degradation of nature.
It finds that risk is increasing rapidly, with more than five new diseases emerging in people every year, any one of which could potentially spark a pandemic.
COVID-19 is at least the sixth global health pandemic since the Great Influenza Pandemic of 1918, also known as the Spanish flu, the 22 experts said.
They stressed that although the new disease has its origins in microbes carried by animals, like all pandemics, its emergence has been entirely driven by human activities.
"There is no great mystery about the cause of the COVID-19 pandemic - or of any modern pandemic", said Dr. Peter Daszak, President of EcoHealth Alliance and Chair of the IPBES workshop.
"The same human activities that drive climate change and biodiversity loss also drive pandemic risk through their impacts on our environment. Changes in the way we use land; the expansion and intensification of agriculture; and unsustainable trade, production and consumption disrupt nature and increase contact between wildlife."
However, pandemic risk can be significantly lowered, the experts said, through greater conservation of protected areas, and other measures to reduce human activities that contribute to biodiversity loss.
This will in turn reduce wildlife-livestock-human contact and help avert the spillover of new diseases.
"The overwhelming scientific evidence points to a very positive conclusion", said Dr. Daszak.
"We have the increasing ability to prevent pandemics - but the way we are tackling them right now largely ignores that ability. Our approach has effectively stagnated - we still rely on attempts to contain and control diseases after they emerge, through vaccines and therapeutics. We can escape the era of pandemics, but this requires a much greater focus on prevention in addition to reaction."
The "business as usual" approach of relying on response to diseases after they emerge is a "slow and uncertain path", the experts charged, and can also threaten biodiversity.
Furthermore, they estimate that economic impacts are 100 times the estimated cost of prevention.
The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) is an independent body comprising more than 130 member Governments.
However, the report has not been discussed and accepted by the IPBES plenary and is not, therefore, an intergovernmental product. It represents the expertise and evidence of the 22 experts who participated in the workshop.
They said it is estimated that another 1.7 million unknown viruses currently exist in mammals and birds, up to 850,000 of which could potentially infect humans.
"Escaping the era of pandemics is possible", the experts said, but will require "a seismic shift" in approach, from reaction to prevention.
Their recommendations include establishing a high-level intergovernmental council on pandemic prevention, to provide decision-makers with the best science and evidence on emerging diseases; and to evaluate the potential economic impacts. Members would also coordinate the design of a global monitoring mechanism.
Countries could also set mutually-agreed goals or targets under an international accord or agreement, with clear benefits for people, animals and the environment.
The report also called for enabling changes to reduce the types of consumption, globalized agricultural expansion and trade that have led to pandemics, for example through taxes or levies on meat consumption, livestock production and other forms of high pandemic-risk activities.