Former U.S. Secretary of Energy Steven Chu: To control the temperature rise within 2 °C, negative carbon emissions must be achieved

"The main risk to humanity is that temperatures will rise, possibly by 2-3°C, which will bring a range of challenges. If it is to be controlled within 2 °C, negative carbon emissions must be achieved. Steven Chu, winner of the 1997 Nobel Prize in Physics and vice president of the World Association of Top Scientists, issued a "wake-up call" at the World's Top Scientists Carbon Conference: Double Carbon Governance Forum held on November 2.

Carbon peaking and carbon neutrality are the hottest topics of the moment and have become the focus of attention of top scientists.

[Things that I spent a lot of effort on when I was the secretary of the U.S. Department of Energy]

At present, the vast majority of greenhouse gases come from the chemical industry, and the development of clean energy is the best way. "The good news is that clean energy is developing rapidly, and in the next 10 to 20 years we will be able to use more clean energy, hopefully to reach 60 percent." Chu said.

Clean energy also faces many challenges, especially the grid and energy distribution is an important issue, because wind power and photovoltaics are unstable and difficult to control artificially, so long-distance transmission is prone to losses. "This requires improving power transmission and transformation technology, which is one of the things I put a lot of effort into when I was secretary of the U.S. Department of Energy."

At the same time, energy storage is also important, but it has not yet been effectively solved. Chu showed off one of his favorite images, an original pumped energy storage device that stores renewable energy as potential energy for water through a pump. This technology is currently used more in Japan, the United States and China, but not every country has such abundant water resources.

When it comes to energy storage batteries, many people will subconsciously think of lithium batteries, but there are actually many other energy storage materials. Chu has been involved in the research and development of new energy batteries in recent years, according to the introduction of cobalt oxide is a good energy storage material, but the price is expensive; China's lithium iron phosphate batteries have many applications, but the energy storage density is not high. In addition, graphite materials are also under development.

【"Artificial cultivation of kelp offshore can increase carbon sinks"]

Academician Zhou Chenghu, academician of the Chinese Academy of Sciences and researcher of the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences, believes that chemical materials have promoted economic modernization, but human activities have increased carbon dioxide emissions. The goal of controlling the global average temperature within 2°C requires cooperation on a global scale. According to reports, in order to reduce carbon emissions, China is building a carbon sink ecosystem, including rational fertilization of crops, expanding afforestation; using ecological engineering to carry out carbon sinks, such as increasing urban greening; and using organisms to capture carbon dioxide.

"If humans can simulate photosynthesis, using carbon dioxide catalysts and nanomaterials technology, to separate water, it can produce endless clean energy." Professor Peidong Yang, winner of the 2015 MacArthur Genius Award, developed nanoparticle-based solar cells and artificial photosynthesis devices known as "liquid sunlight". He shows a photograph of the photosynthesis process of natural plants, and he believes that chemical energy sources such as oil and coal buried in the ground are actually the products of natural photosynthesis hundreds of millions of years ago.

"Artificial cultivation of kelp offshore can increase carbon sinks." Jiao Nianzhi, an academician of the Chinese Academy of Sciences and a professor at the School of Oceanography and Earth sciences at Xiamen University, analyzed how to increase carbon sinks through the ocean. Carbon sink is the concept as opposed to a carbon source. Carbon reduction sources are generally achieved through carbon dioxide emission reductions, and the increase of carbon sinks is mainly based on carbon sequestration technology. A quarter of the carbon currently flows through rivers into the ocean, and marine life itself produces carbon. In his view, China's mariculture scale is the first in the world, although the aquaculture itself has limited carbon sinks, but it provides a place for negative marine emissions. He suggested that an integrated marine and land system could be established to reduce carbon emissions, increase carbon sinks and restore the environment, and form a "China plan" for sustainable development.

Liu Ke, a foreign academician of the Australian National Academy of Engineering and a chair professor in the Department of Chemistry of southern university of science and technology, has been engaged in new energy research for nearly 20 years. He believes that liquids are still the first choice for human beings to use as fuel, energy storage, and transportation, because liquid fuels are convenient for long-term storage, as well as for sea and pipeline transportation, and the transportation costs are low, and human beings have built liquid fuel filling facilities all over the world.

Column Editor-in-Chief: Huang Haihua Text Editor: Huang Haihua Caption Source: Lai Xinlin Photo

Source: Author: Huang Haihua