They increase the permeability of the lymph capillaries. Interstitial fluid enters the lymphatic vessels through the mini valves (which are overlaps of endothelial cells
from multiple lymph capillaries). The valves also prevent the backflow of the lymph from the vessels back to the tissues.
Global warming is the unusually rapid increase in Earth's average surface temperature over the past century primarily due to the greenhouse gases released by people burning fossil fuels.
