The Scientific Perspective of Zero Emissions From biology to architecture, from the arts and humanities to economics, the scientific research behind Zero Emissions Research and Initiatives is dedicated to realizing various innovative ideas. While improving access to water, food, housing, healthcare, employment, energy, and education, it also actively enhances the environment. As people continue to envision a sustainable future that evolves with nature, ZERI has already established an information foundation. This foundation provides us with an endless source of inspiration, guiding us in the ongoing search for solutions to global challenges while meeting the basic needs of all species.
The Five Kingdoms of Nature
Algae
Scientists often describe protozoa as a blend of slime molds and algae. Although we've simplified this, referring to these organisms as algae, we know this is not entirely scientifically accurate.
Algae were among the first organisms with a nucleus. Known as phytoplankton, algae encompass various species that produce energy through photosynthesis, including both eukaryotic and prokaryotic forms. Some algae are related to higher plants, while others evolved independently to harness photosynthesis, seemingly acquiring this ability from cyanobacteria. Algae lack true roots, stems, leaves, or other structures found in higher plants. What sets them apart from bacteria and protozoa is their energy production method, known as photoautotrophy.
Fungi
Fungi include molds and mushrooms, showcasing immense biodiversity, with most species still unknown. For approximately 95% of fungi, we don't even know how to differentiate male from female.
Fungi species vary greatly in ecology, life cycle, and morphology—from single-celled aquatic chytrids to massive mushrooms. The true diversity of fungi is still poorly understood, with estimates suggesting there are between 2.2 million and 3.8 million species, but only 120,000 have been formally described. Recent phylogenetic studies have repeatedly reshaped our understanding of fungal classification, and previously non-fungal organisms (like microsporidia and cryptomycota) have been classified under or closely related to fungi. The relationships within fungi remain unresolved and are a key focus in modern fungal research.
Bacteria
Bacteria are one of the primary groups of organisms, ancient life forms that appeared roughly 3.7 billion years ago. Their defining characteristic is the lack of a nucleus.
Bacteria are omnipresent. Wherever life exists, bacteria are found. They inhabit soil, water, and form symbiotic relationships with other organisms. Bacteria thrive in dense populations, caring for all possible ecosystems. They are present in the air we breathe, the water we drink, and the food we eat, and can be transported by air currents. Bacteria are highly diverse, and the types studied and named by scientists represent only a small fraction. As researchers put it: "You can find them everywhere, and they are far more adaptable than you might think, surviving in virtually any environment."
Plants
Plants are relatively recent arrivals to Earth. Despite millions of undiscovered species, their beauty has inspired poetry, and they have mastered the art of collaborating with animals for reproduction.
It's estimated that there are about 450,000 living plant species, with new species continually being discovered. Mitosis and meiosis are the primary methods of plant cell division, though amitotic processes are also important in growth and development. Sexual reproduction and alternation of generations are key features of plants, but asexual reproduction also plays an important role. Photosynthesis is the main source of energy for plants, forming the foundation of most ecosystems on Earth and driving the flow of materials and energy in the biosphere.
Animals
Animals are multicellular eukaryotic organisms. With few exceptions, most animals consume organic material, breathe oxygen, are capable of movement, and reproduce sexually.
Over 1.5 million living animal species have been identified, with insects representing the largest group at around 1 million species. Animals interact in complex ways with other organisms and their environment, forming intricate food webs. The largest group of animals is worms. Humans are more likely descendants of worms than chimpanzees—a discovery that may not be pleasant but reflects recent findings. In fact, according to Dr. Lynn Margulis’ scientific hypothesis, we are descendants of bacteria, or more accurately, symbiotic bacteria. After all, 10% of our body weight is still made up of bacteria.