Fission, the splitting of atoms, makes the heat that drives our nuclear reactors. Fusion, the fusing together of atoms, powers the stars, including our sun -- which means that fusion already powers Earth, just not in a way that we can control. If we could harness fusion, it would transform our world, producing limitless energy, safely and without emissions -- the holy grail of energy.

Everything in our modern lives has energy inputs and emissions outputs -- and that's certainly the case for our food. It's not just all the energy that powers the equipment required to grow, transport and process our food. And the energy inputs for fertilizer required by global agriculture. But also the emissions from land, and livestock, and particularly from food loss and food waste.

Cement and steel have created the modern world: they make our buildings, roads, machines and products. These two industries emit nearly as much CO2 as our entire electricity system but they're difficult to decarbonize. We'll talk about challenges and potential solutions to do so, including changing their production processes, replacing the coal they now require, and more efficient use.

In Part 1 of this discussion, we heard ideas to decarbonize cement and steel. We'll conclude with a look at fertilizer, which has made modern agriculture possible, and petrochemicals and plastic, which go into nearly every product. Solutions could include switching from oil and natural gas to hydrogen and bioproducts, but the technologies are still in development, and currently expensive.

There are many paradoxes in climate and energy: people want energy for their homes and cars but don't want new power lines or pipelines that could provide it. Nuclear is a zero-carbon energy source yet many climate advocates oppose it. Some states impose EV mandates but prohibit mining for battery metals. We'll look to resolve these with two experts in economics, energy and climate policy.

Six hundred million people in Sub-Saharan Africa do not have modern energy -- so African nations are working to develop their energy resources. For many, the energy they do have comes from hydro. But Africa also has huge volumes of natural gas. Some funders, concerned about emissions, don't want them to develop it. Others consider it essential to lift Africa's people out of poverty.

Sea level has been rising since the end of the last Ice Age, when continental ice sheets began to melt. In island nations and low-lying coastal areas sea level rise is contributing, among other things, to high tide flooding, and saltwater encroaching into farmland and freshwater aquifers. We'll talk about what the future could bring, and ideas of how communities could adapt to sea level rise.

The US energy system, particularly our electric grids and pipelines, is constantly at risk from extreme events, like hurricanes, winter storms, heat waves and wildfires. And increasingly from cyber attacks, from hostile foreign powers and criminal elements. Enough that the energy industry and the US government are investing billions of dollars and working together to counter these threats.

Everything in the modern world relies on the electric grid. To keep the grid reliable, system operators order electricity from dispatchable generation, like coal, gas, hydro and nuclear, to balance intermittent generation, like wind and solar. Together, these must meet our enormous electricity demand, which varies by the second. It's a hugely complicated task, and it's facing real challenges.

For our ongoing 'youth voice' series, we created an energy and climate survey and asked two current and recently graduated university students to help administer it to hundreds of peers across the country, from diverse political backgrounds. The results provide a broad look at the energy and climate opinions, and knowledge, of young Americans -- and will test yours too.

India is the third largest energy consumer and carbon emitter in the world, with the fastest growing energy demand. Today coal makes three-quarters of their electricity, with the other 25% solar and other non-carbon sources. If they follow China's path and develop further on coal, it may be impossible for the world to meet its climate targets -- making India's energy choices of vital importance.

In part 1, we focused on India's electricity, and the potential to expand it using coal and/or solar. We continue with the growth of 2- and 3-wheel electric vehicles in India, the potential to manufacture their batteries domestically, the growth of air conditioning to combat heat waves, decarbonization targets, green building and the importance of efficiency.