By the year 2050, London's climate will resemble Madrid's today; Paris will be more like Canberra; Stockholm like Budapest and Moscow like Sofia, according to a new analysis published Wednesday that relied on optimistic projections.

The changes will be even more dramatic for the world's major tropical cities like Kuala Lumpur, Jakarta, and Singapore which will experience unprecedented climate conditions, resulting in extreme weather events and intense droughts.

The study was carried out by scientists from ETH Zurich and published in PLOS ONE on Wednesday.

Researchers examined the climate of the world's 520 major cities using 19 variables that reflect variability in temperature and precipitation.

Future projections were estimated using established modeling that was intentionally optimistic, meaning it assumed carbon dioxide emissions would stabilize by the middle of the century through the implementation of green policies, with a mean global temperature increase of 1.4 Celsius.

The team then compared climate similarity of current and future cities to one another, and the results make for dire reading.

Across the northern hemisphere, cities in 2050 will resemble places that are over 1,000 kilometers (600 miles) further south towards the equator.

Those closer to the equator won't see drastic warming but will likely have more extremes of drought and rainfall.

Overall, 77 percent of the world's cities will experience a "striking change" in climate conditions, while 22 percent will experience "novel" conditions — ie something that has never before been encountered.

In Europe, summers and winters will get warmer, with average increases of 3.5 celsius and 4.7 celsius, respectively.

While the modeling used in the analysis is not new, the purpose of the paper was to organize that information in a way that will inspire policy makers to act.

"The point of this paper is to try to allow everyone to get a better grasp on what's happening with climate change," lead author Jean-Francois Bastin told AFP.

Bastin, who is from Belgium, added it was not certain that by 2060 his country would experience sub-zero temperatures in winter, a necessary condition for wheat seeds to become activated.

As summer temperatures surge, more people in northern Europe will purchase air conditioners, adding to the strain on electric grids and possibly creating a vicious cycle, he added.

"It's been more than 30 years that most of us have agreed that there is a climate change which is caused by human activity, but still we fail to really transform that in to global actions," he said.

Global warming changes wild plant mix in France
Paris (AFP) July 9, 2019 –

In less than a decade, climate change has altered the mix of plants in the French countryside, with some species thriving at the expense of others less tolerant of heat, researchers reported Wednesday.

A study of almost 2,500 plant species from 2009 to 2017, published in Biology Letters, is the first to document the impact of global warming on flora in France over such a short period.

"There has been a rearrangement of plant communities in France since 2009," Gabrielle Martin from France's Natural History Museum, co-author of the study, told AFP.

"Species that prefer warmer temperatures grow more abundantly and even settle in new areas."

Slender wild oat (Avena barbata), for example, has flourished across a wide range.

At the same time, however, other plants that prefer cooler climes, such as wild buckwheat (Fallopia convolvulus), have declined over the last decade.

Climate change is clearly the driver in each case, the study found.

The data underlying the findings was gathered through a citizen science project called Vigie-Flore.

More than 300 skilled amateur botanists collected data over the nine-year period, noting the presence or absence of France's most common plant species.

Each participant regularly surveyed one or more plots of one square kilometre each.

About a quarter of the area monitored was artificial land cover, 29 percent was farmland, 16 percent were meadows, and 22 percent was forest.

More than 3,000 sites were catalogued, and the evolution of 550 species tracked.

The biggest transformation occurred where the rate of temperature increase was highest, the study showed.

"It's the first time that a change in flora on a national scale is detected over such a short period of time," Martin said.

The impact on individual species varied: some blossomed more, others less; some migrated northward, while others grew taller.

Plant species with shorter, one-year life cycles adapted more quickly to climate change than perennials, trees or bushes. The similar relationship between size and the ability to adapt has been noted in animals too.

As to whether the change observed is good or bad news is "difficult to say," according to Martin.

"Plant diversity has been modified," she said. "These changes certainly have an impact on other organisms in the environment: insects, birds…"

Even if biodiversity does not decline, she added, there would certainly be a knock-on effect on the relationship between species.

When species gravitating toward more favourable conditions "settle in an established community, they modify the interactions — and more specifically competitive interactions — between species," Martin said.