Salt marshes which form a natural defence against the impact of climate change could die out before the end of the century, scientists have warned.
A study into coastal vegetation predicts that warmer temperatures will encourage the plants to grow until around 2075, but a simultaneous rise in sea levels means they are likely to drown by the year 2100.
Researchers said salt marshes are effective at removing carbon dioxide from the air and lock away as much carbon as about a third of the world's forests.
Their loss is expected to contribute to the amount of CO2 in the atmosphere and, consequently, increase global warming.
Scientists at the universities of Edinburgh, Virginia and California created computer models of how salt marshes could respond to higher temperatures and sea levels by combining existing data on rates of plant growth and decay.
Their results suggest that warmer weather would speed up growth in the roots and leaves of the plants, helping to remove more CO2 from the atmosphere for another 60 years.
They said plant decay is forecast to overtake plant growth at the same time and, from about the turn of the next century, rising sea levels would be expected to drown many plants and prevent them storing any further greenhouse gases.
Dr Simon Mudd, of the University of Edinburgh's School of GeoSciences, said: "Salt marshes are extremely effective at removing carbon from our atmosphere and it is worrying that they could all but disappear within the next century."
Previous research had suggested that sea levels would impact on salt marshes, but this study, published in Nature, is said to be the first to predict the combined effect of rising temperatures, CO2 and sea levels.