Elon Musk once said 'We can use Nukes to Warm Mars up' If we extrapolate from that, we can also use Nukes to cool Earth down.
Neutron bombs were intended to detonate at ground level to destroy all humans nearby whilst keeping Buildings mostly unscathed. The difference here is that we could detonate them in the sky instead.
The fiery blast radius would be a few hundred metres. The high energy Neutron radius would be 1000-2000 metres.
High energy Neutron collisions with Carbondioxide would make radioactive Carbondioxide. This newly radioactive compound would Betadecay into single Atoms
Earth's Atmosphere
78.08% Nitrogen
20.95% Oxygen
0.93% Argon
0.03% Carbondioxide
0.0018% Neon
0.0005% Helium
0.0001% Krypton
0.00001% Xenon
As you can see, Carbondioxide is the only natural compound in the Atmosphere
Excess Carbondioxide causes Global warming
On the Periodic table
Carbon has 6 Protons
Nitrogen has 7 Protons
Oxygen has 8 Protons
I have read that high amounts of Radioactive Carbondioxide would be non lethal to Humans
The floor is open to criticism and room for improvement.