The businessman-turned-activist, who has previously donated $1m (£800,000) to carbon removal projects, becomes "an accidental endurance athlete" as he completes his 2,640 mile journey on his 60th birthday.
Canadian entrepreneur Craig Cohon finished a 4,250-kilometre journey across Europe on Monday after walking for five months straight to draw attention to carbon emissions. He also drained his entire pension fund, which amounted to $1 million.