Wildfires in Hawaii have devastated the historic city of Lahaina, the former capital of the islands when they were an independent kingdom.

Hawaii Sen. Brian Schatz, who surveyed the damage, said the city had been “reduced to ashes.” Although the blaze in Lahaina is 80% contained, there is still an active fire. The city remains without power.

At least 67 people have been killed by the fires as search, rescue and recovery operations continue. Gov. Josh Green said hundreds of homes have been destroyed, leaving thousands without shelter.

Lahaina carries deep cultural significance to Hawaiians. King Kamehameha I established Lahaina as his royal residence in the early 19th century.

“It’s absolutely heartbreaking. The recovery process will be long, but we’re committed to these families and communities,” Schatz said on social media.

Thailand, the world’s second largest exporter of rice, is encouraging its farmers to plant less of the crop in a bid to save water — a move that could roil rice markets further following India’s export ban.

Thailand is facing a spate of low rainfall. In an effort to conserve water for consumption, the Office of the National Water Resources (ONWR) has called on the country’s farmers to turn to “planting crops that use less water [which] can be harvested quickly.”

“The cumulative rainfall is about 40% less than normal, which is at high risk of water shortage,” secretary-general of the ONWR, Surasri Kidtimonton, said in a statement released by Thailand’s National Water Administration.

Kidtimonton said the country’s water management needs to “focus on water for consumption,” as well as “water for cultivation mainly for perennial crops.”

Perennial crops are crops that grow back after harvest and need not be replanted every year, unlike annual crops. Rice is categorized as an annual crop.

For every kilogram of rough rice grown, an average of 2,500 liters of water is needed. In comparison, alternative crops like millets require between 650 to 1,200 liters of water for the same amount harvested.

Just last month, India banned exports of non-basmati white rice, a move aimed at ensuring “adequate availability” in domestic markets, the government said.

India is the world’s leading rice exporter and accounts for 40% of global rice trade, and the ban is expected to affect millions.

“Global rice price will have the potential to increase further in the event that rice production in Thailand decreases significantly year on year,” Rabobank’s senior analyst Oscar Tjakra told CNBC.

However, it still remains to be seen whether Thai farmers will follow the directive, said Tjakra.

“Thai farmers might still choose to plant rice on the back of the current high global rice export prices environment,” he said.

Rice prices are already hovering at decade highs, in part due to tighter supplies when the staple became an attractive alternative as prices of other major grains surged following Russia’s invasion of Ukraine in February 2022.

“Thailand often pushes for water conservation, but it has little effect on the use of water as the water rights system has yet to be developed,” said Jeremy Zwinger, CEO of The Rice Trader told CNBC in an e-mail.

BEIJING — In the third high-level U.S. official visit to China in about a month, U.S. special envoy for climate John Kerry emphasized efforts to stabilize the bilateral relationship.

“Now we’re in a place where because of the efforts of President Biden and President Xi to try to stabilize the relationship, we can now I hope, make progress between now and the meeting in the UAE, in December, of COP 28,” Kerry said Tuesday, in opening remarks at a meeting with Chinese Premier Li Qiang.

About a week earlier, Li met with U.S. Treasury Secretary Janet Yellen in the same building. In late June, U.S. Secretary of State Antony Blinken also met there with Chinese President Xi Jinping.

Blinken’s visit brought a thaw to increasingly frigid relations in which climate talks, one of the few areas of cooperation, have even seen temporary suspension.

The U.S. and China are also the world’s largest polluters. In recent weeks, global temperatures have climbed to record highs.

The world faces great “challenges” in responding to climate change, Li said.

“It is incumbent upon China, the United States, and indeed all countries in the world to strengthen coordination with consensus and speed of actions,” he said, according to an official translation of his Mandarin-language remarks.

Earlier on Tuesday, Kerry also emphasized stability in his meeting with China’s top diplomat, Wang Yi.

“Biden is very committed to stability within this relationship and also to achieve efforts together, that can make a significant difference in the world,” Kerry said.

“Our hope is now that this could be the beginning of a new definition of collaboration and the capacity to resolve the differences between us.”

Climate talks between the U.S. and China were temporarily suspended after then-House Speaker Nancy Pelosi visited Taiwan in August last year, drawing the ire of Beijing.

China considers the democratically self-ruled island as part of its territory.

Tensions between the U.S. and China have also spilled over into technology, with U.S. efforts to limit Chinese access to high-end semiconductor technology.

“Of course, pushing for cooperation on climate change is under the larger scope of China-U.S. relations,” Wang said, according to a CNBC translation of the Mandarin.

He said the two countries could resolve problems as long as the dialogue was based on “equality” and with “mutual respect.”

Following the latest U.S. senior official visits to Beijing, high-level Chinese officials are expected to visit the U.S. at an unspecified date.

Since arriving in Beijing on Sunday, Kerry has focused on talks with his climate counterpart Xie Zhenhua. Kerry is set to depart on Wednesday.

Parts of meetings open to the press were tense.

During the meeting with the Chinse premier, Kerry brought up a report of a 52°C (125.6°F) temperature reading in China a few days earlier. Li interjected to question whether it was from an official weather report or “small” media, and whether it was a reading from the ground or air.

“Oh. Well, it may not be,” Kerry said. He said that he’d seen the news on TV and said his point was about the rate of change and predictions for the future.

State-run China News Agency on Monday said an “automatically” recorded temperature from a local weather station showed the Sanbao township in Xinjiang reached a record high of 52.2°C on Sunday.

Europe was gripped by punishing heat waves in the summer of 2022, with wildfires, droughts and deaths highlighting what many around the world already know: Weather extremes can have devastating, real-world consequences.  

When it comes to temperatures in warmer months, the direction of travel seems to be going one way.

The U.K.’s Met Office is projecting that summers in the country will be between 1 and 6 degrees Celsius warmer by 2070, and as much as 60% drier. It adds that global heat waves linked to climate change are likely to increase. Just this week it said last month was the U.K.’s hottest June on record.

The overall picture is challenging. In May 2023, the World Meteorological Organization said there’s “a 98% likelihood that at least one of the next five years, and the five-year period as a whole, will be the warmest on record.”

The consequences of a warmer planet are going to be multifaceted, affecting billions of people — and the world of work is no exception.

A recent report from the Institution of Mechanical Engineers (IMechE) sketched out how employees could be affected as temperatures rise.

“Thermal comfort is very important in a workplace and if it is not achieved, morale, productivity, health and safety will all likely deteriorate,” the analysis said.

According to those involved in the report’s production, warmer working environments can create some very challenging scenarios indeed.

“There’s a whole range of things in addition to just people becoming fatigued and exhausted and not being able to focus on the industrial tasks they’re trying to undertake,” Tim Fox, its lead author, told CNBC.

That includes “increased potential for accidents, because people’s cognitive thinking isn’t as sharp as it would normally be.”

Issues relating to productivity also apply to equipment, facilities and buildings, Fox said. “Overheating ultimately results in economic productivity loss, [it] impacts on national and international economics.”   

Fox and his co-authors are not alone in highlighting the difficulties of a hotter world.

In 2019, the International Labour Organization published a report which contained some sobering details. 

“The economic losses due to heat stress at work were estimated at US$280 billion in 1995,” the U.N. agency said.

This, it added, “is projected to increase to US$2,400 billion in 2030, with the impact of heat stress being most pronounced in lower-middle- and low-income countries.”

The ILO’s report also highlighted which sectors would likely bear the brunt of rising average temperatures.

Those working in construction and agriculture, it said, were “expected to be the worst affected, accounting for 60 per cent and 19 per cent, respectively, of working hours lost to heat stress in 2030.”

Heat stress is a serious matter. The ILO describes it as referring to “heat received in excess of that which the body can tolerate without physiological impairment.”

Other outdoor jobs may be affected, too. In his interview with CNBC, Fox highlighted the potential challenges faced by workers in oil refineries, gas plants and chemical works.

All the above roles, he said, involve “quite a lot of external activity,” with workers also needing to wear personal protective equipment, or PPE, thanks to the nature of their job.

“This clothing can be quite cumbersome … and quite hot to wear, even under cold conditions,” Fox said.

That in turn makes employees “particularly at risk or vulnerable to … these sort of conditions.”

Factories are another area of concern. Fox noted that buildings of this type haven’t particularly been designed with heat ingress — especially extreme heat ingress — in mind.

“They’re full of equipment that’s generating a lot of heat, and it’s very difficult for factories, buildings, big warehouse buildings, to passively cool themselves,” he said.

Air conditioning is common in offices, but that’s not the case everywhere, he added.

Fox noted that office buildings in countries with temperate climates, like the U.K., “can get quite hot” because not a lot of air-conditioning had been installed.

The overall situation appears grave. For many, preparation and adaptation will be crucial.

The IMechE says this will involve “changes to the design of buildings, infrastructure and other physical assets and systems, both with regard to those that already exist and those that are yet to be built or manufactured, as well as the work, educational, leisure and other activities that humans undertake.”

In a statement issued alongside its report in April, the organization said it also wanted an urgent update to “guidance related to heat impacts on the workforce” so firms can come up with plans and enact changes in their working environments.

At the time, Laura Kent, the IMechE’s public affairs and policy advisor, referenced the challenges authorities face.

“We acknowledge that it would be difficult for the Health and Safety Executive to set a meaningful upper temperature limit due to variations between industries in both working conditions, required PPE and workload,” she said.

“However, HSE guidance needs to be updated to support sectors and industry in the development of appropriate strategies.”

The HSE did not respond to CNBC’s request for comment ahead of this story’s publication.

In other parts of the world, plans are being made to ban work when it’s too hot.

In May, for instance, Spain’s Minister of Labour and Social Economy, Yolanda Díaz, tweeted that carrying out “certain jobs during daylight hours” in extreme temperatures would be prohibited.

Speaking to reporters, Díaz said such prohibitions would take effect when AEMET, the State Meteorological Agency, issues red or orange weather alerts.

Citing Spain’s Labour Ministry, Reuters said the move would affect roles in sectors like agriculture and street cleaning. According to Reuters, in the summer of 2022 a street-sweeper in Madrid died from heatstroke.

Trade unions are also making their voice heard when it comes to working in extreme conditions.

Take Unite the Union, which has a presence in Britain and Ireland. It’s listed a range of advice provided by its health and safety representatives to both workers and employers.

Among other things, it stresses the importance of adequate ventilation for internal workspaces, the provision of cover for workers who are in direct sunlight, and stopping all work in extreme conditions.

Among a wide range of actions, Fox stressed the importance of design in creating safe and comfortable working environments in the face of hotter weather.

He said there needs to be a completely new approach to cooling that does not rely on the use of air conditioning, which has a significant environmental footprint.

“We need to explore … more traditional solutions of natural ventilation, use of shade, internal courtyards,” Fox said.

He noted that there’s “an awful lot” that can be done to prepare for the future. Raising awareness would be key. “In many cases, industries and workforces are just not aware that this challenge is coming, and are not preparing for it,” he said.

On top of that, identifying priorities in research and development and updating engineering methodologies and approaches would be needed.

Unless something is done, there will be, “in the coming years and decades, an increase in the economic impact of more extreme heat waves and just the general raising of the ambient seasonal temperature,” Fox warned.