It's difficult to say how the study's results might differ under a slightly less severe warming trajectory, said Thomas Haine, an expert in ocean circulation at Johns Hopkins University who was not involved with the new research.
At last week's meeting here of the Society of Vertebrate Paleontology, another team of U.S.-based researchers looked at a slightly later but somewhat less severe warming period, which happened about 53 million years ago.
Our three warming scenarios represent progressively severe warming (or alternatively modest warming over a progressively longer outlook).
The likelihood of longer lived events (> 35 years) is between 20% and 50%, and the risk of an unprecedented 50 year megadrought is non-negligible under the most severe warming scenario (5-10%).
Of most concern is that severe warming (RCP6.0 and 8.5) will affect marine pelagic biodiversity to a greater extent than temperature changes that took place between either the LGM or the mid-Pliocene and today, over an area of between 50 (RCP6.0: 46.9–52.4%) and 70%RCP8.569.4 73.473.4%) of the global ocean.
That is not insignificant, but that capacity would need to grow by about 200 times to avert severe warming, experts have estimated.
But far more severe warming has taken place over wide regions of northern Eurasia, Canada and Alaska, with temperatures averaging 7 to 10°F warmer in the last 35 years, according to data previously compiled by the NASA Goddard Institute for Space Studies in New York City.
As climate change is expected to cause severe warming events to become more frequent in the future, scientists are beginning to worry that many reefs around the world won't have adequate time to bounce back between bleaching events.
It reported that unprecedentedly high surface ocean temperatures in 1998 as a result of global warming had killed much of the live coral at the Seychelles reefs and warned of the likelihood of even more severe warming, which would ravage the reefs and adversely affect fish diversity, which had already declined by 50% in heavily impacted sites.
Representative spatial models (1 ha resolution) for 3 reforestation designs (i.e. woodlots, typical environmental planting, biodiverse environmental plantings) × 3 timeframes (i.e. 25, 45, 65 years) × 4 possible climates (i.e. no change, mild, moderate, severe warming and drying) were generated (i.e. 36 scenarios) for use within land use planning tools.
The coupled models were used to simulate change in species distributions under three different 90-year climate scenarios (current conditions, moderate warming, and more severe warming and drying) and three different wildfire scenarios (long, medium, and short rotation fire regimes, nominally representing suppressed, historical, and future fire regimes, respectively).
