Net Zero & Energy Transition

Direct air capture, or DAC, is a technology that pulls carbon dioxide straight out of the air so it can be stored away. But running a DAC machine takes energy, and where that energy comes from matters a lot. If a DAC plant is powered by coal or gas, it can create almost as much carbon dioxide as it removes. The biggest climate benefit happens when DAC runs on zero-carbon energy like wind, solar, or nuclear power. Because power grids in most parts of the United States are slowly getting cleaner, DAC and electric technologies like heat pumps and electric cars will keep working better over time.

Making electricity causes about a third of the world's greenhouse gas emissions, and we keep using more electricity every year. Cleaning up the power sector is one of the most important steps toward net zero, because once electricity is clean, we can use it to power cars, buses, and home heating too. The main plan is to build lots more wind and solar power. The tricky part is that the sun does not always shine and the wind does not always blow. This is called intermittency. To handle it, grids can use big batteries, connect regions together so power can be shared, and shift some energy use to times when renewable power is plentiful.

Carbon management means keeping carbon dioxide out of the atmosphere. Nature already does this: plants, soils, oceans, and wetlands soak up CO2 all the time. Carbon dioxide removal, or CDR, means helping nature do more of this or using machines to do it. There are two main technology approaches. Carbon capture and storage, or CCS, grabs CO2 at places like power plants and factories before it escapes, then stores it deep underground. Direct air capture, or DAC, uses machines to pull CO2 that is already floating in the air. Both can help, but they cost money and energy, so most scientists say they should support cutting emissions, not replace it.

Hydrogen is a fuel that can carry energy, a bit like electricity does. It is very light, holds a lot of energy for its weight, and when it burns or runs through a fuel cell, it makes water instead of carbon dioxide. That makes it promising for jobs that are hard to electrify, like heavy trucks, making steel, and storing energy. But here is the catch: today almost all hydrogen is made from fossil fuels, which releases CO2. Green hydrogen is different. It is made by splitting water with electricity from renewable sources, a process called electrolysis.

Lots of companies now promise to reach net zero, but some promises are more advertising than action. Greenwashing is when a company makes itself look environmentally friendly without making real changes. In this lesson, students practice being detectives: they read a company's sustainability plan, check whether its claims hold up, and share what they find with the class. You learn to ask good questions, like whether a company is cutting its own emissions or just buying offsets, and whether its goals have real dates and numbers.