The Victorian writer and mountaineer Leslie Stephen – the father of Virginia Woolf – called the Alps “the playground of Europe”. And so they have been, in winter and summer alike, for many generations. But with excessive warming now placing some of the Alps’ most iconic summits out of bounds, for how much longer can the freedom of Europe’s playground continue?
The basic problem is the warming of the Alps. Snowfall this past winter – especially in the southern Alps – was down by two-thirds from what was once considered normal. The loss of snowmelt is a direct cause of this summer’s brutal drought in the Po valley. Last month, Swiss scientists found that weather balloons were having to rise to 5,184 metres (over 17,000ft), well above the very highest peaks, before they finally reached freezing point.
The central Alps are badly affected too. This year, the snow had all gone by the start of July, at least a month earlier than the previous record. There is no snow on the now closed Matterhorn summit. Meanwhile, the rapid melting of the Theodul glacier nearby has meant that the Italian-Swiss border itself, which traditionally follows the drainage divide between north and south, has had to be shifted significantly in Italy’s direction as the glacier has shrunk.
Higher temperatures mean less ice, including less permafrost; less ice means more rockfalls; and more rockfalls mean more fatalities. The worst accident this summer has been on the Marmolada glacier on the northern slopes of the highest peak in the Italian Dolomites. Eleven climbers were killed when a block of ice and rock plummeted down the glacier without warning. The Marmolada has lost 80% of its volume since 1950, and may disappear altogether in another 15 years. Other Alpine glaciers face similar fates, with widening crevasses causing further dangers.
Half of all mountaineering accidents in France occur on the highest mountain in the Alps, Mont Blanc. So dangerous has the main route from Chamonix up Mont Blanc become that in June many local guides suspended all ascents after another rockfall fatality. Traditionally, Alpine climbers have set off in the early hours to ensure that conditions are frozen and firm. That is now frequently impossible because temperatures are too high, adding to the danger.
The other problem is the attrition of mass tourism in this increasingly fragile environment. Three years ago, many were shocked by pictures from the Himalayas of climbers queueing to ascend the final ridge of Mount Everest. Similar scenes have long been familiar in the Alps too.
Around 120 million tourists visit the Alps in a typical year. Most visitors stay in the valleys and hotel complexes. Many others choose a widely proliferating variety of outdoor activities. One Chamonix guide accuses tourists of climbing Mont Blanc simply for a selfie on the summit. In 2019, a ban had to be imposed on paragliders landing there.
In the Alps, the 21st century’s increasingly head-on collision between industrial tourism and the climate crisis is destroying some of the very environments that have attracted so many to the high mountains in the first place, as well as generating ever larger numbers of accidents. To close the playground of Europe would be unenforceable and unfair, as well as economically devastating. But without collective self-denial and behaviour change, an already bad situation will simply get worse.
Marine scientists monitoring the Great Barrier Reef say they have recorded the highest levels of coral cover in 36 years in the north and central areas, but warned any recovery could be quickly overturned by global heating.
The Australian Institute of Marine Science’s annual long-term monitoring report says the fast-growing corals that have driven coral cover upwards are also those most at risk from marine heatwaves, storms and the voracious crown-of-thorns (COTS) starfish.
Global heating is accepted by scientists as the reef’s biggest long-term threat.
Earlier this year, unusually hot ocean temperatures caused the first ever mass bleaching during a La Niña year – a natural climate phase that should have given corals a respite.
The first ever mass bleaching on the reef was recorded in 1998, but since then corals were hit in 2002, 2016, 2017, 2020 and again earlier this year.
The prognosis for the reef’s future under climate change, the report said, was one of increasingly frequent and longer lasting marine heatwaves, with the ongoing risk of COTS outbreaks and tropical cyclones.
“Mitigation of these climatic threats requires immediate global action on climate change,” the report said.
Dr Mike Emslie, who leads the Australian Institute of Marine Science monitoring program, told the Guardian: “The fact that we have had four bleaching events in the last seven years and the first one in a La Niña year is really concerning.”
Surveys are carried out by towing divers over reefs at a standardised rate, recording corals, bleaching levels, COTS and the number of coral trout and sharks.
About half of the 87 reefs surveyed for the report were carried out before the most recent bleaching event unfolded in February and March this year.
“The effects of the 2022 mass bleaching event are still unfolding, and its impact will only be known over the coming months,” the report said.
Aerial surveys carried out in March by the Australian Institute of Marine Science and the Great Barrier Reef Marine Park Authority covered 750 individual reefs.
The fast-growing acropora species of branching and plate-like corals that were pushing coral cover up were also preferred prey for COTS, he said.
In the northern parts of the reef, the monitoring data showed coral cover averaged 36% – a record high, with the lowest levels in the region at 13% recorded in 2017.
Coral cover averaged 33% in the central area – another record high compared to the 2019 low of 14%.
In the southern region, the average coral cover dropped from a 2021 estimate of 38% to 34%.
While bleaching was widespread across the reef in February and March, Emslie said the heat stress had not reached levels likely to cause corals to die.
“To get at the impacts [of the latest bleaching] we won’t know until we do in-water surveys over the next few weeks.
“But bleaching does have sublethal affects and will affect the physiology of the corals because while they bleach they have been starving.”
He said there was evidence that even when corals did not die from bleaching, the phenomenon could reduce their ability to reproduce, slow their growth and make them more susceptible to coral disease.
He said it could take a year or more for those sublethal effects to become apparent.
The scientists behind a new database of more than 400 extreme weather attribution studies have performed an essential service. This piece of work, drawing together every study of this type, ought to galvanise a greater sense of urgency around policymaking and campaigning. It shows that intense heatwaves, hurricanes, droughts and floods have all been made far more likely by greenhouse gas emissions, which trap the sun’s heat and put more energy into weather systems. And it spells out the alarming unpredictability as well as the extent of global heating’s consequences.
Carbon Brief’s analysis reveals:
• 71% of the 504 extreme weather events and trends included in the map were found to be made more likely or more severe by human-caused climate change.
• 9% of events or trends were made less likely or less severe by climate change, meaning 80% of all events experienced some human impact. The remaining 20% of events and trends showed no discernible human influence or were inconclusive.
• Of the 152 extreme heat events that have been assessed by scientists, 93% found that climate change made the event or trend more likely or more severe.
• For the 126 rainfall or flooding events studied, 56% found human activity had made the event more likely or more severe. For the 81 drought events studied, it’s 68%.
First published in July 2017, this article is the fifth annual update (see endnote) to incorporate new studies. The aim is that it serves as a tracker for the evolving field of “extreme event attribution”.
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It is relatively well accepted that climate change can affect human pathogenic diseases; however, the full extent of this risk remains poorly quantified. Here we carried out a systematic search for empirical examples about the impacts of ten climatic hazards sensitive to greenhouse gas (GHG) emissions on each known human pathogenic disease. We found that 58% (that is, 218 out of 375) of infectious diseases confronted by humanity worldwide have been at some point aggravated by climatic hazards; 16% were at times diminished. Empirical cases revealed 1,006 unique pathways in which climatic hazards, via different transmission types, led to pathogenic diseases. The human pathogenic diseases and transmission pathways aggravated by climatic hazards are too numerous for comprehensive societal adaptations, highlighting the urgent need to work at the source of the problem: reducing GHG emissions.