4 . Plastic is everywhere in our modern world. Its toughness makes it an extremely useful material from household items to vehicle parts, but that same toughness makes it hard to break down for recycling or disposal (处理). However, Japanese scientists at the University of Tokyo have developed a new plastic material that can be broken down more easily and can self-heal and remember past shapes.

Based on a kind of plastic called an epoxy resin vitrimer, which is brittle (脆性的), the new plastic has a huge range of advantages. Once scratched (刮划) with a knife, it can completely patch itself up after being heated to 150 ℃ for just 60 seconds. When shaped into the shape of a crane, then flattened, it can fold itself back into the crane shape by being heated up. It does all of this much faster than others of its type.

The new plastic can also break down easier. Even if it’s thrown into the environment, it still has less of a problem than other kinds of plastic, which the team demonstrated by placing it in seawater for 30 days. It biodegraded (生物降解) by 25% and released something that is eatable for ocean life.

The new plastic is more resistant to breaking. It can also repair itself, and can recover its original memorized shape. It even biodegrades safely in a ocean environment, according to Shota Ando, a researcher of the study.

The material can be used in a variety of applications. “Building materials for roads and bridges are often composed of epoxy resins mixed with compounds (化合物) such as concrete and carbon,” said Ando. “By using the new plastic, these would be easier to maintain as they would be stronger and healable using heat. Unlike conventional epoxy resins, this new material is hard but flexible, so it could also be expected to strongly bond materials of different hardness and stretch.”

5 . Men’s consumption habits are worse for the planet than women’s, according to a new study. For the study, consumption-based greenhouse gas (GHG) emissions were measured for the average individual, the average single male, and the average single woman. These were 6, 9, 10, and 8.5 tonnes per capita per year respectively, and more than half of those amounts were due to food, holidays, and furnishings.

What’s interesting is that single men and women spend similar amounts of money on consumer goods, but men’s choices lead to 16% more GHG emissions than women’s. That is because they choose to spend money on things like cars and driving, rather than taking public transportation or trains, as women are more willing to do. More of men’s money goes toward alcohol, tobacco, and eating out, while women often spend money on clothes, home furnishings, and health-based purchases.

Curiously, there were no differences in the carbon footprints of men’s and women’s diets. While men tend to eat more meat, women make up for that in dairy products, which are also carbon-intensive foods.

Lead study author Mannikin Okayama says she wasn’t surprised by the findings because previous research had showed similar differences between single men and women regarding energy use. Instead, she expressed surprise at the fact that more studies haven’t been done on gender differences in environmental impact. “There are quite clear differences and they are not likely to go away in the near future.”

The purpose of the study was to examine where individuals could make changes to their consumption habits in order to shrink their carbon footprints. The researchers looked for ways that would require minimal additional spending, so as to be more accessible to a greater number of people. They found that only switching to plant-based diets and train-based holidays can reduce emissions by 40%.

Policy-makers would do well to pay attention to this if they want to get serious in the fight against global warming.

6 . Schools in US are huge consumers (消费者) of energy. According to ENERGY STAR, K-12 schools spend more than $ 6 billion every year on energy, far more than the amount spent on other resources, and at least 30 percent of this energy is used inefficiently or needlessly.

Realizing that, some schools are looking for measures to save energy in several ways, from low-cost adjustments, such as turning off lights in unused rooms, to large-scale projects, such as turning to green equipment.

As solar energy (太阳能) is becoming a more financial choice for powering buildings, more schools are making the move toward the renewable energy and using solar panels (电池板) on their rooftops. According to an online solar marketplace Energy Sage, schools have their strong points to use solar energy. They often have the kind of enough space, suitable locations that are perfect for setting up solar panels.

In September 2020, a nonprofit Generation 180 released its third edition of a study on solar use in US schools. The findings showed that more than 7,300, or 55 percent, of K-12 public and private schools used solar energy, the number has increased by 81 percent since 2014.

They also described how solar schools were saving millions in energy bills, and provided several cases to show the increased savings achieved by solar-powered school districts. For example, an Arkansas school used its every year’s energy savings of nearly $ 100,000 to increase its teachers’ salaries.

The Interstate Renewable Energy Council, which tracks the number of K-12 schools with solar equipment and helps schools go solar, says on its website that schools with solar setups have an opportunity to educate students about clean energy, and show them that they are doing something for students’ and the planet’s health and future.

Third-party ownership also makes funding for 79 percent of schools to use solar energy possible, meaning a majority of schools don’t have to spend large amounts of money but can get the rewards of solar energy.

9 . In 2018, the state of California was on fire. Alexandria Villasenor, who was 13 at the time, witnessed the destruction of Northern California’s Camp Fire, which would go on to burn more than 150,000 acres of land. Villasenor was scared. “That’s when I found out how important climate education was,” she reflected. “And just how much we lacked climate education these past couple of years.”

Villasenor, now 15, is determined to have a bigger conversation. She quickly realized the fight requires international, government-level changes. For her, what started as local concern turned into a year-long protest in front of the United Nations’ New York City headquarters and a global campaign for more compulsory climate education. She sat on a bench in front of the headquarters, pleading for the world’s leaders to take climate change seriously.

Her action received national attention, with millions of other students around the world joining in the movement. “It’s completely unacceptable to not learn anything about our planet and our environment in school, after all the young people would ‘inherit’ the Earth.” Villasenor said, “That’s why I think that climate education is so important, and that’s why I focus a lot on it now.”

Right now, Villasenor is working with the Biden-Harris administration on its climate plan, which has promised to center the needs of young people and communities most impacted by climate change. She even spoke at the 2020 Democratic National Convention. “That was definitely a huge moment when I realized that people were listening to the voices of me and youth climate activists,” Villasenor said.

When she isn’t connecting with her fellow youth activists or holding elected officials accountable to the climate concerns of their young voters, Villasenor is like most other teens. “My favorite thing to do, of course, is sleep.” she said. “I like to read a lot. I like fantasy books, normally. I also like to write.”

Today I am honored to give a speech titled Changes Begin With You.

Thank you for your listening.