{A1} (Figure SPM.2). More than 37,000 established 
alien species have been introduced by human activities 
across all regions and biomes of Earth, with new alien 
species presently being recorded at an unprecedented 
rate of approximately 200 annually. Studies with evidence 
of negative impacts exist for more than 3,500 of these 
species, which are categorized as invasive alien species. 
The proportion of established alien species known to be 
invasive varies among taxonomic groups, ranging from 
6 per cent of all alien plants to 22 per cent of all alien 
invertebrates. Twenty per cent of all impacts are reported 
from islands. A disproportionate number of documented 
negative impacts have been reported in terrestrial realms, 
especially in temperate and boreal forests and woodlands 
and cultivated areas (including agricultural land). About 
one quarter of documented negative impacts have been 
reported from aquatic realms, especially from inland surface 
waters/waterbodies and shelf ecosystems. In addition to 
their impacts on nature, about 16 per cent of invasive alien 
species have negative impacts on nature's contributions to 
people, and about 7 per cent on good quality of life.
 <Section-header> KM-A1 People and nature are threatened by 
invasive alien species in all regions of Earth  </Section-header> 

SUMMARY FOR POLICYMAKERS
The thematic assessment report on
INVASIVE ALIEN SPECIES
AND THEIR CONTROL
KM-A1 People and nature are threatened by 
invasive alien species in all regions of Earth 