system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: what's the significance of reaching ignition of nuclear fusion?
gpt
TL;DR: We made a huge step in a decades long attempt to solve the world's energy problems.

Context: A fusion power generator would provide cheap, clean, safe, scalable energy. It would solve the climate crisis and the wars and fighting over oil. We have been working towards this for decades, but it's really hard.

Basically, there are four big milestones that need to be reached to make generation by fusion reactors a reality:

1. Achieve fusion.

2. Get that fusion to set off other fusion.

3. Get all that fusion to release more energy than required to start it.

4. Harness that energy (and still have more than you started with after loses).

Step 1 is comparatively easy and we first did it in 1932, and a 12 year old recently broke a record by being the youngest to achieve fusion. The breakthrough that has been making the news is that we have finally reached step 2. We got fusion to set off more fusion. This is a big fucking deal, but fusion isnt solved. The same experiment only released 70% of the energy that went into it, so we're close to step 3, but not there yet.

To talk about it in analogy, we have been trying to cook our dinner over a campfire. For decades we've been able to get newspaper burning but have been struggling to get any sticks on fire. We finally got some sticks to catch and light other sticks, but we still need to work on building and maintaining a fire long enough to cook with.