Know better. Do better.

Finding new places to put solar power plants can be a challenge, but the U.S. city of Annapolis has come up with a solution: The old garbage dump.

The Maryland landfill, closed 20 years ago, "just sat there as a liability", said David Jarrell, the city's public works director. Now, capped and covered with grass it has 50,000 solar modules, the city has "changed a liability into an asset," he told correspondent Carey Biron.

As ever-cheaper solar energy costs and the U.S. Inflation Reduction Act spur new investment in renewables, solar panels are turning up in a range of innovative new places - including on old toxic waste sites.

But as some cities rush to meet their ambitious climate action goals, not all are finding it quite as easy as they had hoped.

The Norwegian capital of Oslo in 2016 set a radical target: to halve its emissions within four years, a plan it called "demanding yet achievable".

Three years after the deadline, Oslo has made huge strides in electrifying public transport, restricting diesel and petrol cars, and building parks and dozens of kilometres of cycle lanes. 

But it got barely halfway to its 2020 goal - and its new aim, to cut emissions 95% by 2030 - is similarly in question. That's in part because the city's goals depend on national actions out of its control.

Oslo's struggles raise a broader question: Where is the right balance between goals that are ambitious enough and yet achievable too?

In Ecuador, the government is taking steps to crack down on illegal gold mining which it has declared a national security threat.

But indigenous critics say the effort appears more focused on securing legal mining concessions and the financial benefits they bring than protecting indigenous people and their land and forests.

Patricio Meza, leader of the CONAIE Indigenous organization, said evictions of illegal miners have tended to occur in areas where mining concessions have been awarded, which he said was an example of the state's interest in protecting the industry over local communities.

Brazil's Congress, meanwhile, has for the first time backed the sale of carbon credits from sustainable logging concessions granted on state-owned forest land - a new revenue stream for such projects and one designed to boost interest in them.

But the move comes as carbon credits generated by forestry projects face scrutiny due to land rights issues and a lack of benefits for local communities.

"A growing body of research indicates that no real additional protection is being offered by many of the (carbon credit) projects," said Eugênio Pantoja of IPAM, a nonprofit working on sustainability in the Amazon.

See you next week,

Laurie