"Aggressive mitigation" refers to taking strong and forceful actions to reduce or counteract a problem or risk. It means implementing intense and proactive measures to tackle the issue at hand effectively. Full definition
The time has come to proactively prepare for those impacts and to place efforts to build climate resilience on equal footing with aggressive mitigation efforts. (innovationfiles.org)
Keeping the temperature increase that small will require aggressive mitigation, he said. (scientificamerican.com)
If there's any doubt why continued melting is interesting: it means sea level will keep rising even with aggressive mitigation 8 ^ . (planet3.org)