It is easy to sing the blues over green energy.

Government budgets are in disarray. Subsidies are under attack, and climate change is suddenly a dirty word.

But all is not lost. Not by a long shot. Here are eight reasons to be optimistic about the future:

1/ Heavy hitters are entering the game. Google, Warren Buffet and others didn't reach their lofty levels by making mistakes. When they show interest, perhaps we should pay attention.

2/ The Department of Defense, saying our dependence on oil is a security issue, is deeply committed to going green. With a budget of $664 billion, the military should have some influence: If there is doubt, remember the Internet originally was invented for military purposes.

3/ Big Business is on board. Walmart and other companies are discovering that going green - either through renewable power such as solar or by becoming more energy efficient - adds to their bottom lines. Take a look at Walmart's 2011 sustainability report.

4/ Professional sports is getting up to bat: Hockey, baseball, football, basketball and other professional sports is a $19 billion per year enterprise that is gaining a green tint.

5/ Government agencies are pushing it through new programs and initiatives, such as "America's Next Top Innovator," a Department of Energy effort to find The Next Big Thing in clean energy.

6/ Energy conservation is going mainstream. Lowe's, Home Depot, Costco and other retailers are selling energy-efficiency and renewable energy off their shelves. Home builders include it in their sales pitches and awareness is growing.

7/ Costs are coming down. As clean energy grows, oil prices climb and technology advances, costs are decreasing faster than projected. It won't be long - next year, perhaps? - that solar achieves parity.

8/ California's requirement that utility companies get 33% of their power from solar, wind and other renewable energy sources by 2020. The mandate is incentive for more investment in clean energy in the state.