Not OP but short answer: In 40 years, we are reasonably likely to have: functional immortality (cured natural death), brain augmentation, AI/machines able to do many things for us, fusion/renewable-based energy abundance, and more. In almost every measurable way the world is better now than it was 20 years ago, and 20 years before that. This is likely to continue.

Climate change is concerning, but totally addressable with technology. We absolutely can fix ground water, ocean warming, carbon ratios. It involves will, resources, and the technology to be thoughtful of how we impact the planet, instead of randomly doing it as side effects. There are some "trivial" fixes for many issues that can be implemented if we decide we want to (paint 1/4 the sahara white, solar shades in space, etc). They are not hard and if things get bad we will take them more seriously.

Healthcare affordability is essentially a policy issue, but there is no reason in 40 years that healthcare can't be effectively free with AI/Robotics driving down the cost.