SAKU, Japan: Winding past rice paddies and lazily blowing its whistle along bubbly creeks, a two-car train in rural northern Japan is the latest entrant in the battle against global warming.

• 佐久,日本:缠绕过去稻田和懒洋洋吹了哨子泡沿着小溪,一两节车厢在北部郊区,是日本最新的笔试在对抗全球变暖。