Germany aims to become carbon-neutral by 2045 and cut 65% of emissions by 2030 compared with 1990, but current reduction rates are falling short, the first biennial report by the council showed.
The energy sector contributed almost half of Germany's 27% CO2 reduction between 2000 and 2021, while the construction, transport and industry sectors, after a good start, have been sluggish to cut emissions in the past decade.
The council said the transport and construction sector needed to be restructured to reverse the trend.
A change in consumer behaviour was also necessary and the government should impose strict limits on emissions volumes for all sectors, it added.
Nearly 200 countries will gather in Egypt next week for climate talks, as pressure for tougher action to tackle global warming grows.