Can we grow vegetables without sunlight? Scientists come up with a new method | Environmental News

Hello everyone, this is the 30th issue of the Environmental Trumpet column. In this issue, we have collected the following environmental research and news worth reading:

1) Extreme heat accelerates human aging

2) People are driving giant beetles to extinction for chocolate

3) Can you grow vegetables without sunlight? Scientists come up with a new method

4) Batteries made of paper? They can be used to grow flowers after they are degraded

Extreme heat accelerates human aging

Recently, a study published in Science Advances found that long-term exposure to extreme high temperature environments can cause changes in human DNA and accelerate biological aging .

Elderly people are particularly affected by extreme heat. | AP Photo/Lynne Sladky

The research team analyzed blood samples from more than 3,600 elderly people and used the epigenetic clock to predict a person's biological age by detecting levels of DNA methylation.

DNA methylation refers to the addition of small methyl groups to DNA, which affects gene expression without changing the DNA sequence. There are many factors that affect DNA methylation, including age, gender, diet, and lifestyle. Based on the methylation level, the epigenetic clock can calculate the biological age of the human body - a young man may be more fragile than an old man.

Through research, researchers found that the biological aging rate of the elderly living in high-temperature areas is significantly faster than that of the elderly in cool areas . Compared with cool weather, people's biological age is even 14 months older than their actual age under the "barbecue" of extreme high temperatures (temperatures above 32.3°C) for no less than 140 days a year, which is equivalent to the impact of smoking and alcoholism.

Given that many elderly people suffer from a variety of minor ailments, their tolerance for high temperatures may be less than research expects, and even in not-so-hot weather (such as an environment around 27°C), their bodies may age faster.

For chocolate,

People are driving giant beetles to the brink of extinction

Recently, scientists discovered that one of the world's largest insects, the Goliathus, is facing the risk of extinction, and the reason for its extinction is related to chocolate.

About 70% of the world's cocoa comes from West Africa | Greenshoots Communications

Under the influence of global warming, the production of cocoa in West Africa has declined. As the main raw material of chocolate, the reduction in cocoa production is bound to cause price fluctuations in the global chocolate market. In order to alleviate the shortage of production, people in West Africa have begun to further expand the scope of cocoa plantations , which has also destroyed many valuable forest resources.

The giant horned beetle is one of the "treasures" living in the forests of West Africa - its number can reflect the health of the local forest . A large number of it means that the forest is growing well, and vice versa.

The giant horned beetle is widespread in many countries in West Africa | C.Nahaboo/Flickr

Because adult giant horned beetles feed on tree sap , in order to investigate their distribution, scientists chose to track trees that exude sap. Unfortunately, it turned out that two species of giant horned beetles are now facing the risk of extinction. One of them may have become extinct in parts of West Africa, and the other has lost about 40% of its habitat.

In addition to habitat destruction caused by the expansion of cocoa plantations, the insect trade has also contributed to the decline of the giant horned beetle. Scientists have found that people are selling giant horned beetles on Facebook, eBay and other platforms.

Can you grow vegetables without sunlight?

Can vegetables grow without sunlight? Now scientists have explored a new way to grow crops: electric farming .

One of the great advantages of electric agriculture is that it reduces the need for lighting in agriculture | F. Jiao

Electric agriculture is agriculture that uses electricity to ensure the growth and maturity of crops. Without sunlight, plants cannot synthesize organic matter through photosynthesis, so electric agriculture takes a different approach - using electrolysis to decompose carbon dioxide (CO2) into carbon monoxide (CO), which eventually forms acetate . Plants first absorb the acetate, and then metabolize it to synthesize organic matter such as sugars.

Currently, lettuce seedlings can use acetate to stay alive, but they won't grow | Elizabeth Hann

Currently, researchers have successfully used this method to cultivate algae and some biological resources that do not photosynthesize, such as mushrooms and yeast. Researchers have also found that crops such as tomatoes and lettuce can also use acetate to sustain life , but if they want to grow continuously, they need to improve their metabolic process.

Compared to crops synthesizing organic matter through photosynthesis, electric agriculture sounds a bit wasteful of electricity. The advantage of electric agriculture is that it is not highly dependent on land and water resources, and can provide food sources in low light or extreme environments . At present, electric agriculture is still in the development stage and faces many challenges, the primary of which is energy consumption . The process of electrolysis to produce acetate consumes a lot of electricity. It is estimated that in the United States, if only electric agriculture is used to feed the entire nation, its electricity consumption will be about 5 times the current total electricity consumption in the United States. In addition, the current operation efficiency of electric agriculture is low, and how to improve efficiency is also a major problem.

Batteries made of paper? They can be used to grow flowers after they are degraded

In January this year, the paper battery exhibited by Singapore startup Flint won the Best Sustainability Award at the International Consumer Electronics Show (CES). The company's product is a battery made of paper.

Paper batteries are incredibly thin and light | Courtesy Flint

Paper batteries abandon the lithium, nickel and cobalt used in traditional batteries, and instead use zinc, manganese and cellulose as the main materials of the battery . The principle of paper batteries is based on the redox reaction of metals such as zinc and manganese. In the battery, zinc serves as the negative electrode, manganese as the positive electrode, cellulose paper as the base material, and hydrogel is filled in to form ion channels. When the battery is working, zinc loses electrons to undergo an oxidation reaction, and the electrons flow to the positive electrode through the external circuit. The manganese ions at the positive electrode gain electrons to undergo a reduction reaction, thereby generating current.

Flint developed this battery with environmental issues in mind. Paper batteries are biodegradable - after removing the sealed shell, the battery can be broken down into non-toxic components. The lithium, nickel and cobalt used in traditional batteries often cause environmental problems during mining and processing, and are difficult to degrade. The metals such as zinc and manganese used in paper batteries are more common in the natural environment and can also be absorbed by plants.

Paper batteries are biodegradable and can be used to further nourish plants | Katie Collins/CNET

At present, paper batteries are mainly used in small electronic products. However, considering that paper batteries are flexible and can be folded at will, they will also be considered for use in foldable mobile phones in the future.

Author: Xiao Xiaoze

Edited by: Yellowtail Pollock