Dubai's record rainfall, and other urban transformation stories you need to read

Air traffic and transport in Dubai were brought to a standstill this month after United Arab Emirates (UAE) and Oman were hit by a storm that caused the heaviest rainfall since records began 75 years ago.

The downpour, which scientists said was exacerbated by climate change, led to flooding on highways, trapped people in their homes, and closed government offices and schools for several days.

At least 20 people were reported to have died in Oman, and there was one death in the UAE.

In Al Ain, a city bordering Oman, a record 254mm of rainfall was recorded, the largest in a 24-hour period since records began in 1949.

Mark Howden, Director at the Australian National University's Institute for Climate, Energy & Disaster Solutions, told Reuters global warming had raised the temperature of the seas around Dubai, while also warming the air above the city.

"This increases both potential evaporation rates and the capacity of the atmosphere to hold that water, allowing bigger dumps of rainfall such as what we have just seen in Dubai."

Nearly half of major cities in China are experiencing "moderate to severe" levels of subsidence, according to a study published in the journal Science. Land subsidence is a phenomenon that occurs when groundwater has withdrawn from certain types of rocks, including types of sediments.

Subsiding puts millions of people at risk of flooding, especially as sea levels rise.

The study found that 45% of China's urban land is sinking faster than 3mm per year, with 16% sinking at a rate of more than 10mm per year. This is primarily driven by declining water tables and the weight of the built environment.

It comes as several cities in the country's densely populated Pearl River Delta, in the south of the country, were flooded following record-breaking rains.

On 22 April, rescuers in Guangdong province evacuated trapped residents and deployed helicopters to save villagers caught in landslides, Reuters reported.

The below chart from 2014, shows the potential area of flooding under different sea-level rise scenarios.

The world's most sustainable cities have been revealed in the Global Destination Sustainability Index, with Gothenburg, Sweden; Oslo, Norway; Glasgow, Scotland; Bordeaux, France and Goyang, South Korea, making up the top five. The index ranks cities against 69 indicators, including recycling rates, air pollution levels and quantity of cycling paths.

More people in the centre of Paris now travel by bike than by car, according to a study by the Institut Paris Region. It found Parisians use bicycles for 11.2% of their trips within the city centre, compared to just 4.3% of journeys done by car.

Spanish airlines are increasing capacity by 13% compared to last year, in anticipation of a record summer season.

In March, new home prices in China fell at their fastest pace since 2015, Reuters reports. The city of Zhengzhou has urged residents to sell their "second-hand" homes to a state-owned company and buy new ones to decrease new home inventories and stimulate the local property sector.

Construction of the first high-speed rail in the US using Japanese bullet trains is one step closer, after the governments of both countries indicated their support for the plan. President Joe Biden is looking to revive interest in the project connecting Dallas and Houston in Texas.

The world will be 70% short of low-carbon offices by 2030 as demand outstrips supply, according to a new report from real estate firm JLL. The green tipping point predicts decarbonization legislation and lease renewals will fuel demand, creating a significant shortfall. Low-carbon materials and design techniques can help cut carbon emissions from buildings and building materials, the World Economic Forum says.

By 2050, we need to produce 70% more food, but only 10% of farmable soil will be available, writes Arama Kukutai, CEO of Plenty. We need to change how we feed the world and indoor vertical farming has the potential to bring local food production to any community, but so far has proved difficult to scale up, here's why.

Public procurement is perceived to be a barrier to innovation in many countries, which prevents suppliers with reliable solutions from competing for public sector contracts. The G20 Global Smart Cities Alliance has released a foundational model policy with practical steps for cities worldwide to spark innovation through procurement.