Title: Environmental effects of aviation
Content:  and 2006, greenhouse gas emissions from aviation increased by 87% in the European Union. In 2010, about 60% of aviation emissions came from international flights, which are outside the emission reduction targets of the Kyoto Protocol. International flights are not covered by the Paris Agreement, either, to avoid a patchwork of individual country regulations. That agreement was adopted by the International Civil Aviation Organization, however, capping airlines carbon emissions to the year 2020 level, while allowing airlines to buy carbon credits from other industries and projects. In 1992, aircraft radiative forcing was estimated by the IPCC at 3.5% of the total man-made radiative forcing.
Title: Environmental effects of aviation
Content:   In 1999, the IPCC estimated aviation's radiative forcing may represent 190 mW/m2 or 5% of the total man-made radiative forcing in 2050, with the uncertainty ranging from 100 to 500 mW/m2. If other industries achieve significant reductions in greenhouse gas emissions over time, aviation's share, as a proportion of the remaining emissions, could rise. Alice Bows-Larkin estimated that the annual global emissions budget would be entirely consumed by aviation emissions to keep the climate change temperature increase below 2 °C by mid-century. Given that growth projections indicate that aviation will generate 15% of global emissions, even with the most advanced technology forecast, she estimated that to hold the risks of dangerous climate change to under 50% by 2050 would exceed the 
Title: Airline
Content:  average jet in 2005. Despite continuing efficiency improvements from the major aircraft manufacturers, the expanding demand for global air travel has resulted in growing greenhouse gas (GHG) emissions. Currently, the aviation sector, including US domestic and global international travel, make approximately 1.6 percent of global anthropogenic GHG emissions per annum. North America accounts for nearly 40 percent of the world's GHG emissions from aviation fuel use. CO2 emissions from the jet fuel burned per passenger on an average 3200 km airline flight is about 353 kilograms (776 pounds). Loss of natural habitat potential associated with the jet fuel burned per passenger on a 3200 km airline flight is estimated to 
Title: Environmental effects of aviation
Content:  industry's fuel efficiency improvements of 1% per year. Between 1960 and 2018, RPKs increased from 109 to 8,269 billion. In 1992, aircraft emissions represented 2% of all man-made emissions, having accumulated a little more than 1% of the total man-made  increase over 50 years. By 2015, aviation accounted for 2.5% of global emissions. In 2018, global commercial operations emitted 918 million tonnes (Mt) of, 2.4% of all emissions: 747 Mt for passenger transport and 171 Mt for freight operations. Between 1960 and 2018, emissions increased 6.8 times from  to 1,034 million tonnes per year. Emissions from flights rose by 32% between 2013 and 2018. Between 
Title: Flight shame
Content:  About 2.5 percent of global human carbon emissions come from commercial flights. Additionally, planes emit other gases such as nitrogen oxide and water vapour as contrails that also have an environmental impact. When the flight shame movement started, the volume of flights was projected to expand, although the aviation industry was taking steps to decrease their emissions.
Title: Greenhouse gas emissions
Content:  Approximately 3.5% of the overall human impacts on climate are from the aviation sector. The impact of the sector on climate in the late 20 years had doubled, but the part of the contribution of the sector in comparison to other sectors did not change because other sectors grew as well.
Title: Climate change in Sweden
Content:  Global civil aviation accounts for 4–5% of total greenhouse gas emissions and these emissions are increasing. Greenhouse gas emissions from air travel are substantial for high-income countries like Sweden. Chalmers University Gothenburg developed methodology to calculate Swedish aviation emissions. The climate impact of aviation, is effected in addition to CO2 emissions by emissions of nitrogen oxides above 8000 meters and the warm aircraft emissions forming ice crystals. Total emission were estimated by calculating the CO2 emissions by 1.9 for international flights, and by 1.4 for domestic flights. Calculation excluded emissions from the production of fuel which is 10-20% in the EU. The Swedish population's air travel emission based 
Title: Environmental effects of aviation
Content:  carbon budget in conventional scenarios. In 2013, the National Center for Atmospheric Science at the University of Reading forecast that increasing levels will result in a significant increase in in-flight turbulence experienced by transatlantic airline flights by the middle of the 21st century. Aviation emissions grow despite efficiency innovations to aircraft, powerplants and flight operations. Air travel continue to grow. In 2015, the Center for Biological Diversity estimated that aircraft could generate 43 Gt of carbon dioxide emissions through 2050, consuming almost 5% of the remaining global carbon budget. Without regulation, global aviation emissions may triple by mid-century and could emit more than 3 Gt of carbon annually under a high-growth, business-as-usual scenario. Many countries have pledged emissions reductions for the 
Title: Airborne fraction
Content:  The airborne fraction is a scaling factor defined as the ratio of the annual increase in atmospheric CO2 to the emissions from anthropogenic sources. It represents the proportion of human emitted that remains in the atmosphere. The fraction averages about 45%, meaning that approximately half the human-emitted is  absorbed by ocean and land surfaces. There is some evidence for a recent increase in airborne fraction, which would imply a faster increase in atmospheric for a given rate of human fossil-fuel burning. Changes in carbon sinks can affect the airborne fraction.
Title: Individual action on climate change
Content:  be made to work properly. Flying is responsible for 5 percent of global warming. Compared to longer flight routes, shorter flights actually produce larger amounts of greenhouse gas emissions per passenger they carry and mile covered, so individuals may consider train travel instead but this can be more expensive due to aviation subsidies. Airplanes contribute to damaging our environment since airplanes cause greater air pollution as they release carbon dioxide along with nitrogen oxides, which is an atmospheric pollutant. Tailpipe emissions lead to changes in the amounts of the greenhouse gases ozone and methane. Avoiding night-flights may help, as contrails may account for over half of aviation's climate change impact.

Question: what percentage of global man-made co2 emissions comes from worldwide aviation?
Answer: 4 percent cumulative effect.