• As concerns about sustainability mount, discussions about how and where we grow food have become increasingly pressing.
• While there is a sense of excitement regarding the potential of tech-driven operations, there's also an argument to be had for going back to basics.

From oranges and lemons grown in Spain to fish caught in the wilds of the Atlantic, many are spoiled for choice when it comes to picking the ingredients that go on our plate.

Yet, as concerns about the environment and sustainability mount, discussions about how — and where — we grow our food have become increasingly pressing.

Last month, the debate made headlines in the U.K. when the second part of The National Food Strategy, an independent review commissioned by the U.K. government, was released.

The wide-ranging report was headed up by restaurateur and entrepreneur Henry Dimbleby and mainly focused on England's food system. It came to some sobering conclusions.

Its executive summary said the food we consume — and the way we produce it — was "doing terrible damage to our planet and to our health."

The publication said the global food system was "the single biggest contributor to biodiversity loss, deforestation, drought, freshwater pollution and the collapse of aquatic wildlife." It was also, the report claimed, "the second-biggest contributor to climate change, after the energy industry."

Dimbleby's report is one example of how the alarm is being sounded when it comes to food systems, a term the Food and Agriculture Organization of the UN says encompasses everything from production and processing to distribution, consumption and disposal.

According to the FAO, food systems consume 30% of the planet's available energy. It adds that "modern food systems are heavily dependent on fossil fuels."

All the above certainly provides food for thought. Below, CNBC's Sustainable Future takes a look at some of the ideas and concepts that could change the way we think about agriculture. 

Growing in cities

Around the world, a number of interesting ideas and techniques related to urban food production are beginning to gain traction and generate interest, albeit on a far smaller scale compared to more established methods. 

Take hydroponics, which the Royal Horticultural Society describes as "the science of growing plants without using soil, by feeding them on mineral nutrient salts dissolved in water."

In London, firms like Growing Underground are using LED technology and hydroponic systems to produce greens 33-meters below the surface. The company says its crops are grown throughout the year in a pesticide free, controlled environment using renewable energy.

With a focus on the "hyper-local", Growing Underground claims its leaves "can be in your kitchen within 4 hours of being picked and packed."

Another business attempting to make its mark in the sector is Crate to Plate, whose operations are centered around growing lettuces, herbs and leafy greens vertically. The process takes place in containers that are 40 feet long, 8 feet wide and 8.5 feet tall.

Like Growing Underground, Crate to Plate's facilities are based in London and use hydroponics. A key idea behind the business is that, by growing vertically, space can be maximized and resource use minimized.

On the tech front, everything from humidity and temperature to water delivery and air flow is monitored and regulated. Speed is also crucial to the company's business model.

"We aim to deliver everything that we harvest in under 24 hours," Sebastien Sainsbury, the company's CEO, told CNBC recently.

"The restaurants tend to get it within 12, the retailers get it within 18 and the home delivery is guaranteed within 24 hours," he said, explaining that deliveries were made using electric vehicles. "All the energy that the farms consume is renewable."

Grow your own

While there is a sense of excitement regarding the potential of tech-driven, soilless operations such as the ones above, there's also an argument to be had for going back to basics.

In the U.K., where a large chunk of the population have been working from home due to the coronavirus pandemic, the popularity of allotments — pockets of land that are leased out and used to grow plants, fruits and vegetables — appears to have increased.

In September 2020 the Association for Public Service Excellence carried out an online survey of local authorities in the U.K. Among other things it asked respondents if, as a result of Covid-19, they had "experienced a noticeable increase in demand" for allotment plots. Nearly 90% said they had.

"This alone shows the public value and desire to reconnect with nature through the ownership of an allotment plot," the APSE said. "It may also reflect the renewed interest in the public being more self-sustainable, using allotments to grow their own fruit and vegetables."

In comments sent to CNBC via email, a spokesperson for the National Allotment Society said renting an allotment offered plot holders "the opportunity to take healthy exercise, relax, have contact with nature, and grow their own seasonal food."

The NAS was of the belief that British allotments supported "public health, enhance social cohesion and could make a significant contribution to food security," the spokesperson said. 

A broad church

Nicole Kennard is a PhD researcher at the University of Sheffield's Grantham Centre for Sustainable Futures.

In a phone interview with CNBC, she noted how the term "urban agriculture" could refer to everything from allotments and home gardens to community gardens and urban farms.

"Obviously, not all food is going to be produced by urban agriculture, but it can play a big role in feeding local communities," she said.

There were other positives, too, including flood and heat mitigation. "It's … all those benefits that come with having green spaces in general but then there's the added plus, [which] is that you're producing food for local consumption."

On urban farming specifically, Kennard said it provided "the opportunity to make a localized food system" that could be supported by consumers.

"You can support farms that you know, farmers that you know, that are also doing things that contribute to your community," she said, acknowledging that these types of relationships could also be forged with other types of farms.

Looking ahead

Discussions about how and where we produce food are set to continue for a long time to come as businesses, governments and citizens try to find ways to create a sustainable system that meets the needs of everyone.

It's perhaps no surprise then that some of the topics covered above are starting to generate interest among the investment community.

Speaking to CNBC's "Squawk Box Europe" in June, Morgan Stanley's global head of sustainability research, Jessica Alsford, highlighted this shift.

"There's certainly an argument for looking beyond the most obvious … ways to play the green theme, as you say, further down the value and the supply chain," she said.

"I would say as well though, you need to remember that sustainability covers a number of different topics," Alsford said. "And we've been getting a lot of questions from investors that want to branch out beyond the pure green theme and look at connected topics like the future of food, for example, or biodiversity."

For Crate to Plate's Sainsbury, knowledge sharing and collaboration will most likely have a big role to play going forward. In his interview with CNBC, he emphasized the importance of "coexisting with existing farming traditions."

"Oddly enough, we've had farmers come and visit the site because farmers are quite interested in installing this kind of technology … in their farm yards … because it can supplement their income."

"We're not here to compete with farmers, take business away from farmers. We want to supplement what farmers grow."