The report looked at the projected impact of a 2C world temperature increase on rugby.
“As the science shows, the world is heating up and likely to surpass a 1.5-degree increase in global average temperatures by 2026. Without large-scale reductions in emissions, a two-degree increase in global average temperatures is a real possibility,” it said.
It found that with a 2C rise, 11% of the 111 stadiums looked at across the world are at risk of annual marine submersion, with 30% experiencing increased wind/cyclone activity.
Marine submersion projections were based on rises in sea levels, storm surges and annual flooding data.
England, which has 1.94m rugby players and 1,700 clubs, is at “increased risk” of heavy rainfall and flash flood frequency.
Nottingham Rugby Club saw its ground badly flooded in January this year following Storm Henk.
The 147-year-old club launched a fundraising appeal because its insurance would not cover the repair costs due to the ground being built on a floodplain.
Grass pitches in England are also under threat from a destructive fungal disease called pyricularia from southern Europe, which is now found in southern England and Wales.
Six out of the 10 rugby nations investigated – which also included Australia, South Africa, France, Fiji and New Zealand – will face 10 additional days when they cannot play due to high temperatures exceeding 35C.
Other stadiums at risk of marine submersion according to the report are Perth’s Optus Stadium, The HFC Bank Stadium in Fiji’s capital Suva, two Japanese stadiums in Higashiosaka and Kitakyushu, as well as five stadiums in New Zealand in Napier, Nelson, Dunedin, Whangarei and Tauranga.