THE THEMATIC ASSESSMENT REPORT ON INVASIVE ALIEN SPECIES AND THEIR CONTROL
23SUMMARY FOR POLICYMAKERS
1970 1980 1990 2000 2010 2019
1
10
100
1000
YEAR
Trend in global annual economic
cost with confidence intervals
Cumulative documented costs of
biological invasions 1970-2017
Brown tree
snake, Guam
Has caused the local
extinction of most
resident populations of
Guam's 25 bird species
Chytrid fungus,
Central America
Has contributed to
severe global declines
of amphibians, including
global extinctions
Buffel grass,
Australia
Restricts access to
culturally important
sites, making it
difficult to transmit
traditional knowledge 
European
shore crab,
North America
Has decimated
commercial shellfish
beds in New England
and Canada 
Japanese
knotweed, Central
and Northern 
Europe
Reduces abundance and
species richness of native
plant and soil-inhabiting
species 
Nile perch,
Lake Victoria
Has caused the global
extinction of many endemic
cichlid fish species
Little fire ant,
tropical Africa
Has caused local extinctions 
of forest floor and leafchewing invertebrates
Branched pipe coral,
South America
Overgrows native corals,
causing community-wide
mortalities and local extinctions
Contributed 
to
60%
X 4
every
decade
85%
Extinctions Economic cost Good quality of life
The economic cost of biological
invasions has increased fourfold
every decadeb
Invasive alien species have a negative
impact on good quality of life
in 85% of casesc
In billion
No data
$1 $10 $100
50.9%
vertebrates 32.4%
invertebrates
1.2%
microbes
15.4%
plants
218 invasive alien species have
caused 1,215 local extinctions
of native species
Invasive alien
species
causing local
extinctions
In 2019, the estimated global annual
economic cost of biological
invasions was $423 billion
Known impact of invasive alien
species on good quality of life
AVERAGE ANNUAL COST IN BILLION $
0
CONSTITUENTS OF GOOD QUALITY OF LIFE Freedom of choice Material and immaterial assets Health Safety Social/cultural relationships
10
0
40
50
20
30
10
0
Negative impact
Positive impact
PERCENTAGE OF DOCUMENTED IMPACTS
Invasive alien species have contributed 
solely or alongside other drivers of 
change to 60% of recorded global 
extinctions, of which 90% occurred 
on islandsa
Figure SPM 3 Extent of the problems caused by invasive alien species. 
Illustrative examples of the impacts of invasive alien species on native species (red; left column), on the economy (blue; centre column) 
and on good quality of life (yellow; right column). The top row illustrates the documented numbers of global and local extinctions of 
native species to which invasive alien species have contributed (left); the rate of increase in the economic cost of biological invasions 
per decade (centre); and the percentage of cases where the impact of invasive alien species on good quality of life is reported as 
negative (right). The map in the centre row shows the documented cumulative economic cost of invasive alien species per IPBES 
SUMMARY FOR POLICYMAKERS
19SUMMARY FOR POLICYMAKERS
BACKGROUND
A5 