For millennia man has been changing the landscape, hacking and burning forests and ploughing up grasslands.

ECONOMIST: Climate change

Yes, it is true that one farmer ploughing up another 500 acres of Nebraska does indeed change the supply of wheat and thus the prices of wheat around the globe.

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"When the enemy trained a gun on me, a round shot struck the ground not more than thirty feet in front of me, ploughing up the turf many yards, " he wrote on May 2, 1862.

FORBES: War Story

Mr Cassidy cites the case of Nike, the sports-shoe giant, which recently eliminated Colorado from its list of possible sites for a new corporate head office after local people protested over the ploughing up of a scenic hilltop.

ECONOMIST: The suburban West

Ploughing fields opens up organic matter to oxidation and the release of nitrogen held in the soils.

BBC: Thames archive reveals long nitrate rise

They are responsible for patching up, rebuilding, stripe-painting, putting up signs and, most winters, ploughing snow.

ECONOMIST: America��s highways