What does 'net zero' mean? Our climate change glossary will help you sound smart

(CNN)The whole world seems to be talking about the climate crisis, thanks to months of wild weather and new science showing that we need to act quicker than we previously thought to avoid the worst consequences.

As leaders prepare to meet in Glasgow, Scotland, next month for crunch talks, they'll be using a lot of technical lingo. The terminology isn't particularly communicative and can be daunting.
Even the name of the summit -- COP26 -- sounds more like a bad police drama than a climate event. (First pointer: COP is short for Conference of the Parties to the UN Convention on Climate Change. It convenes global leaders, scientists and negotiators on climate, and usually takes place annually. The "26" means Glasgow will be the 26th meeting.)
    Here are other terms to know to keep up with the talks, understand what's at stake and, most importantly, sound smart around the dinner table.

      Net zero emissions

      Net zero emissions can be achieved by removing as much greenhouse gas from the atmosphere as what's emitted, so the net amount added is zero. To do this, countries and companies will need to rely on natural methods -- like planting trees or restoring grasslands -- to soak up carbon dioxide (CO2), the most abundant greenhouse gas we emit, or use technology to "capture" the gas and store it away where it won't escape into the atmosphere.
      Dozens of countries have already pledged to achieve net zero by mid-century and there is huge pressure on countries that haven't yet to do so by COP26.

        Negative emissions

        To save the world from the worst effects of climate change, scientists say it's probably not enough to reach net zero. Net negative emissions is the situation where the amount of greenhouse gas removed from the atmosphere is actually more than the amount humans emit at a given period of time.

        Carbon sinks

        A container of young silver firs at a forest tree nursery in Pockau-Lengefeld, Germany.
        This is a reservoir that absorbs carbon dioxide from the atmosphere and locks it away.
        Natural sinks like trees and other vegetation remove CO2 from the atmosphere through photosynthesis -- plants use the carbon dioxide in the atmosphere to grow. The ocean is also a major carbon sink because of phytoplankton which, as a plant, also absorbs carbon dioxide.
        Scientists say preservation and expansion of natural sinks such as forests are crucial to reducing emissions.
        There are also artificial carbon sinks that can store carbon and keep it out of the atmosphere. More on that below.

        Carbon capture and storage

        Technology to remove and contain carbon dioxide from the atmosphere is known as carbon capture and storage. Carbon is usually captured at source -- directly from coal, oil or gas as it burns -- but new technology is being developed to literally suck carbon from the air.
        In both cases, the carbon can be stored, usually buried in reservoirs underground or below the floor of the sea, in what are known as artificial carbon sinks. Some scientists warn that it could be risky to inject so much carbon underground, and this process isn't currently used on a large scale. The Global CCS Institute says just 27 commercial facilities are fully operating worldwide, while more than 100 others are in development. But other experts say CCS is necessary to put a real dent in our emissions.
        There are many ways to capture and store carbon. Here are some of them:
        • Carbon dioxide capture and storage (CCS) is a process in which CO2 produced by heavy industry or power plants is collected directly at the point of emission, compressed and transported for storage in deep geological formations.
        • Carbon capture, utilization and storage (CCUS) refers to the collection of CO2 from industrial sources, which is then used to create products or services, such as manufacturing fertilizer or in the food and beverage industry. (Fun fact: This CO2 can be pumped into your beer to make it fizzy.)
        • Direct air capture and storage (DACS, DAC or DACC) is a chemical process which removes CO2 directly from the air for storage. There were 15 direct air capture plants operating worldwide, according to a June 2020 International Energy Agency (IEA)