Climate change could shrink vital tropical rainfall belt.
Er, no. The article speaks loudly on little evidence. Evidence extracted from a single stalagmite can only extend our existing knowledge as applied to that location. Belize is at 17° north, a latitude only occasionally visited by the equatorial rain belt, the inter-tropic convergence zone (ITCZ).
Existing understanding for the equatorial rain belt is that it will expand north-south, not shrink. With global warming, its area of ocean water above 26° C is increasing. Saturated air above that temperature is unstable relative to the top of the troposphere, so guaranteeing convection within the belt and stronger tropical cyclones at its periphery, implying more transported rain, albeit more erratically.
At the same time, increasing energy in regional ocean-continent cycles would be influencing the climate in Belize. Rather mischievously, the author hints at large climate refugee movements into North America and out of sub-Saharan Africa.
However most of the population dependent on the ITCZ is in South Asia and Southeast Asia. Increasing energy in the system is predicted to increase the suck-and-blow of the Asia-Australia monsoon oscillation, varying the position of the ITCZ in Southeast Asia. Already, the Indian Ocean Dipole (the Indian Ocean equivalent of the Pacific's El Niño Southern Oscillation) increasingly correlates with ENSO. The two major dipoles disrupt and displace the ITCZ east-west. Over the past year, the IOD has been bringing drought to Indonesia and Northern Australia, and the ensuing wet season is currently (February 2020) sparse.
"Half of world's beaches could vanish by 2100" ... Which doesn't include the increasing use of beach sand to make concrete.
Yes, famous beaches and the constructions sitting on them are doomed to vanish as the seas rise and storms increase. However the beach sand itself is travelling along the beach rather than out to sea. In general, a storm wave crashing up onto the shore has far more turbulence to carry sand upslope than the same wave to carry sand downslope as it ebbs back out to sea. Hinterlands with a low grade will see their beaches encroach inland. Many hinterlands consist of dune sand blown up from the beach previously can look forward to fine new beaches. With similar potential benefit, the hinterlands of arid coasts such as western Australia and Namibia are heavy with dune sand blown from the desert inland.
DBB has already explained how easily-extracted sand deposits within truckable distance of the cities are running out. Seeing as the world consumes more than seven billion m³ of concrete every year, that implies a lot more extra trucking – and theft of public sandscapes.
Local geography makes a difference. Much of the west coast of the Americas is quite steep
The report speaks of the sand moving up and down slope on a seasonal basis. It goes on to say that because the slope is steep there, some sand is lost down past the 44 foot depth, below which (seasonally big) wave action can no longer lift sand back up again.
"scientists seek the cause of blue whales' mystery skin lesions"
The article reports finding detectable levels of POPs, man-made "persistent organic pollutants". However being detectable doesn't imply that the level is harmful. The article does imply that the pollutants have been concentrated as they travel up the food chain. One would expect that a functioning metabolism would excrete ingested foreign chemicals in urine and faeces. Lipid-like organics such as DDT do accumulate in fat, of which a whale has plenty, but you would not expect toxic levels to accumulate on the skin.
Whales do accumulate a wide variety of parasites on their skins, partly because they have no means, short of migration, to scrape off their attached ecosystems. Infestations of more hostile species may well displace otherwise friendly skin ecosystems, causing ailments such as the blisters in the photograph. Once having migrated to warmer waters, whales manage to lose that layer of their skin and its burden, presumably because there are more grazing animals in warmer water to nibble off their surplus skin. www.atlasobscura.com/articles/why-whales-visit-tropical-spas-every-year
It seems that large animals often tolerate the presence of small ones feeding on its parasites and actively seek out the cleaners. On a scuba visit to the Great Barrier Reef, our guide took us to a "cleaning station", where if we opened our mouths and waited, little fish (cleaner wrasse) came and picked at our teeth. The underwater sound, "tink, tink" as our teeth collided is memorable.
Six-fold jump in polar ice loss lifts global oceans
We should take a pinch of salt with anything we read on m.phys.org, and not choose it as a source of authority. In this case it is the journalism rather than the science that is at fault.
The author is jumping too far into the future when he writes that the ice caps have "sloughed off" 6400 km3 of ice in 25 years. But instead of the implied avalanche of calving kilometre-thick icebergs, so far almost all of that loss has been meltwater. The required, and much dreaded acceleration of the ice streams due to current warming is expected, but the date and rate of its acceleration has yet to be revealed. In Greenland, rain and meltwater sink through the ice, either to intermediate shear layers or to the base where it either drains to sea or buoys up the ice above its basins. In West Antarctica, the sea is penetrating underneath the partly-buoyant Thwaites Glacier and melting it from below. Concern here is that it will cease to buttress the much larger WAIS ice stream feeding from the land. In both cases, the capacity to accelerate is known but not the degree or timing.
The standard (International) unit for measuring such volumes is the cubic kilometre, which all readers can imagine. Instead, the author prefers to use the gosh factor, trying to make the quantities seem unimaginably big by speaking breathlessly of billions and billions and trillions. When he can only quantify the rate of flow in "Olympic pools per second", either the author or the intended reader is contemptibly stupid. At least he is not speaking in terms of elephants of mass!
He encapsulates an error inside a quote, so that we can gather that either the scientist is hopelessly wrong or the journalist is hopelessly lazy. "If Antarctica and Greenland continue to track worst-case climate warming scenarios, they will cause an extra 17 cm of sea level rise by the end of the century". Wrong ballpark. At that date, sealevel rise due to BAU melting is more likely to measure in metres with the rate in cm/a.
He reiterates the denialist hope that achieving carbon neutrality will stop sea level rise. What, despite the enduring increase in temperature? Seeing as sea levels were still rising in the 1800s due to the temperature rise of 6000 years before, the current temperature step-up is likely to dominate continuing sea level rise for millennia beyond any achievement of carbon neutrality.
Polar sea level will sink as the ice caps melt even as the other oceans rise. The shape of the geoid (aka mean sea level) is determined by the mass distribution, so the removal of such a large mass will lower the geoid for hundreds of kilometres around. There is a further lowering expected in the immediate vicinity of the ice shelf, where the lost large mass above sea level used to attract upward. Further, the ground will rise in isostatic response to the loss of load, eventually at centimetres per year.
Readers interested in the melting of the ice sheets should read the peer-reviewed paper that the m.phys article discusses. They use the more strict unit of mass flow, Gt/yr, which can be read as km3/a of meltwater.
"Greenland's melting ice raised global sea levels by ... in two months"
The article being referred to is interpolating the data series between the expiry of GRACE and the launch of GRACE-FO satellites. The analysis is conservative, without surprises. It derives a convenient, if noisy, estimate for the acceleration of the ice sheet melt, ~8 km3/a/a (JPL), which would contribute an acceleration of 0.016 mm/a/a to the rate of sealevel rise (currently 3.4 mm/a). It seems too conservative to my eye, surely much more than that. However it does contradict the figure quoted by the journalist.