Carbon dioxide equivalents from air transport were approximately 154 kilotonnes in the third quarter of 2021, according to a preliminary calculation of emissions from Iceland's economy. This is an increase of 111% from the second quarter of the year and 27.7% higher than in the third quarter of 2020. Emissions in the third quarter of 2021 were 78% lower than emissions in the third quarter of 2018, when emissions from flight transport were highest at 711 kilotonnes.
More foreign airlines serviced Iceland this summer, but emissions caused by these companies are not inside the economy's emissions figures shown above.
Emissions from household vehicles were 180 kilotonnes in the third quarter of 2021, which is 13.2% higher than in the same quarter last year. This value is somewhat lower than 2018 levels, when emissions from household cars peaked.
Emissions from the manufacturing sector (NACE C) are noticeably higher in the third quarter of 2021 as compared with other quarters in the data. Preliminary values for the current year are estimated from imports of raw materials and exports of manufactured goods. The value for the third quarter of 2021 is 591 kilotonnes, which is 15.4% higher than in the third quarter last year and 28.3% higher than in the second quarter this year.
This increase could be due to delays in exports of manufactured industrial products. The increase could also be from an increase in production, and consequently emissions, due to favorable market prices. Export figures show a noticeable increase in aluminum exports between the second and third quarters of 2021, which is reflected in increased emissions from metal manufacturers (NACE sector C24). There is also a significant increase in the export of refined silicon and an increase in imports of raw materials for production. These include quartz sand and coal. Emissions from sector C20 are noticeably higher. The total emissions for the first through third quarters this year are comparable with emissions for the same period in previous years.