Today planet Earth on its orbit is at the point furthest from the sun. On 4 July the Earth is at aphelion, 152,500,000 km from the sun. On 3 January the Earth is on its nearest point to the sun, 'only' 147,500,500 km. The dates of aphelion and perihelion advance at about 30 minutes per calendar year. Thus in 11,500 years from now the situation will be reversed. Then the Earth will be closest on 4 July and thus northern hemispheric summers will be warmer and winters colder.